Rat Infestation

As is true of any other type of pest invasion it is important for the individual homeowner to recognize the telltale signs of a rat infestation, whether planning on dealing with the problem himself or calling in professional exterminators.

Rat Infestation Signs: Droppings

One of the first indicators of the presence of rats is their droppings. A rat infestation in house can be determined or eliminated by a careful examination in dark corners and along baseboards for rat feces.

Rat droppings can be anywhere between a half inch to three quarter inches in size (contrasted against the rice grain sized feces of the house mouse) depending on which species is involved. The black rat’s fecal pellets are roughly a half inch long; those of the brown rat are larger commensurate with their greater size, each pellet can be ¾ of an inch long.

When fresh, rat feces of both species have a slight sheen and dark color. Also depending on the species of rats involved, droppings may be found singly or in groupings. As droppings age, they turn grey in color and have a crumbly consistency.


Other indications of the presence of rats are urine trails or puddles and “grease” stains on walls and baseboards. These stains are caused by the natural oils and dirt on the rats’ fur rubbing off on surfaces they travel on or through, small barely distinguishable stains are likely caused by mice, rats leave larger stains on these surfaces.

Rats are the poster children for incontinence; they dribble urine with almost every step they take and pass feces with a similar abandon. Rat urine leaves a musty scent, most noticeable in small enclosed spaces.

Evidence of gnawing

Rats are inveterate nibblers who can bite through all but metal, glass and thick plastic containers. Even if droppings are not readily apparent, if chew marks are found on food boxes or sacks, a rat or mouse infestation is all but a certainty. Dry pet food bags or boxes should be inspected as well; rats are particularly drawn to “meaty” smells characteristic of both cat and dog chow.Good starting points in a survey for signs of rat infestation are the areas involved in food storage and preparation. Rats exploit human populations for ready food and water sources, the pantry or kitchen is a magnet for rat activity. Droppings and grease stains may be visible in kitchen cabinets and drawers; but food containers should also be inspected for signs of gnawing.

Rats have been known to gnaw into non-food items such as soap. If an item has a smell attractive to the rodents, they will nibble away on it.

Another kitchen location for rat sign is under the sink. If plumbing is at all leaky, the opportunistic rodents will avail themselves of the ready water supply. They have also been known to chew through plastic water pipes. This extends to other plumbing, including the bathroom and laundry rooms. Carefully inspect the areas around any pipes or faucets for droppings urine, grease marks and signs of chewing.

Rats have incisors that never stop growing; they gnaw on non-edible materials to wear the teeth down. Wood is a favorite target of rat gnawing. Sometimes teeth marks are readily apparent on exposed wooden surfaces; the newer areas will be light in color, revealing the untreated wood beneath the surface. As these marks age they darken, so that new markings can be readily distinguished from old. Even when obvious gnaw marks are not visible, sawdust and small chunks of wood near baseboards may indicate the presence of a rat colony.

Rat signs: Sound

Another, often overlooked sign of a rat infestation is sound. Rats are nocturnal animals that tend to be the busiest while humans are asleep. Nevertheless, the alert homeowner will be able to hear squeaks, scratching, rustling and scampering sounds as the rats travel about in search of food and build their nests. Listening for these sounds just before bedtime can help to verify a rat problem.


Rats nest in warm, dry, out of the way places including boxes, inside cabinets, behind dressers (and in drawers, especially those not often accessed), even the casings of computer towers. They will also climb up into the insides of furniture to nest in the stuffing.

Rats also take advantage of the warmth found near refrigerators, stoves and dishwashers, hiding behind or even inside of their housings.

Rats prefer soft, warm and fuzzy nesting materials, which they transport to the nest site and stuff into their chosen space. Nesting materials include grasses, fabric, furniture stuffing, quilt batting, absorbent cotton, shredded paper and twigs. Inspect stored fabrics for chew holes, quilt and cotton batting for any sign of urine and droppings, whenever possible store such inviting nesting materials in durable plastic storage containers that can be sealed airtight.

Pay Attention to Your Pets

The presence of rats can generate greater excitability among household pets. If your dog or cat spends time listening intently or pawing at baseboards and walls, it is highly likely that they are responding to the activity of rats within the structures. They also respond to the odor of unseen rodents, although they may alert to old rat smells as well as more recent ones.

Rat trails

In dusty areas, rat paw prints may be visible along baseboards and walls. Where dust is not allowed to accumulate, one can test for the presence of mice and rats by sprinkling talcum powder next to baseboards, leaving it for a few days. If rats or mice are traveling along these paths, the talcum will bear evidence of their habitual traffic.

Incidentally, inspection for rat infestation signs should not be limited to interior spaces alone. Food gardens or nearby agricultural fields are strong rat attractions. Plants and their fruits should be inspected for signs of chewing, and the surrounding soil checked for evidence of rat droppings. Outside structures used for grain storage should be regularly inspected for evidence of rats as well.

Rat Infestation Risks

Rats present health risks other than direct transmission of diseases. Their urine and fecal pellets can contaminate food and water supplies rendering them inedible and undrinkable. Rats also have mites and fleas that can readily jump to domesticated pets, and in some cases, onto people.Rats are perceived in most of the world as dirty animals that spread disease to humans and domesticated animals. It is true that a number of serious diseases and illnesses are transmissible from rodent to human or pets. Companion animals can fall victim to some of these diseases, other maladies use cats and dogs as vectors to spread to humans.

However, the risks of rat infestation are not just to health alone. The tendency of rats (and mice) to chew on electrical wiring is claimed to be a common cause of structural fires. Rats are not inconsiderable sources of structural damage.

Rats not only gnaw to wear down their incisors, they will also chew through walls and other impediments to reach food, or to create a more direct route to a water or food source. They may also chew into structures to expand or create nesting sites. Rats can cause substantial damage to walls, baseboards, roof rafters, subflooring, ceilings and support beams, especially when a large colony of rats is responsible for the infestation.

What to Do In Case of a Rat Infestation

Let’s say you’ve done your due diligence and have determined that your home or business has been infested by rats. What do you do?

The first thing NOT to do is panic.

The first thing to do is determine whether or not it is necessary to hire a professional to deal with the problem or fight it yourself. This decision is not always a simple one; the size of the infestation is a consideration. If the rat population invading your structure is small, do-it-yourself efforts may be successful both in terms of cost and efficacy.

If the infestation is severe or you simply don’t feel you can cope with the elimination of the rats, you should consider enlisting the services of a professional rat control company. Money spent on experts can often turn out to be more cost effective in terms of greater efficiency and reduced costs of traps, poisons and cages. In individual stress alone it may well be worth it to leave dealing with the infestation in the hands of qualified technicians.

Exterminators can also often help home and business owners rat proof their buildings after the infestation has been dealt with. They frequently also provide ongoing monitoring against future invasions.

There are other considerations which impact the decision of hiring rat control specialists or going the DIY route. You must determine if you are willing to solve your rat problem via toxic, inhumane efforts, or if you prefer humane, environmentally friendly and pet safe alternatives.

Rat poisons are not only considered inhumane due to the length of time it takes rat poison to effect a kill; they present significant risks to the health of pets, wildlife and young children via secondary poisoning.

The U.S. Government has recently limited access to certain types of rat poisons and has banned others outright. Consumers are no longer allowed to buy certain rodenticides, and regulations have been implemented that limit the types and designs of rat traps that can be used by the public. Poisonous baits must now be housed in tamper proof bait stations that limit the access of wildlife, pets and children to the rat poisons contained within.

Poisons can also leach into soil and water putting other animals and humans at risk. Also, rats dying of poisoning often retreat to their nests, which means that dead rodents will decompose in areas inaccessible to humans. This can lead to long lasting, very unpleasant odors within a home or business.

Thanks to the societal “Green Revolution” many rat control specialists are now turning to extermination and control methods which are considered more environmentally friendly, humane as well as less toxic to non-target animals. Careful research into the types of exterminators found in your area, and the methods employed is vital.

Rat Infestation Solution?

Rats breed and colony size increases when the supply of food and water is steady and abundant in quantity. In order to prevent future infestations follow these guidelines:In terms of rat control an ounce of prevention is worth more than a pound of cure. After an infestation has been dealt with—or better yet, before it establishes itself– the key to a permanent solution to rat infestations is to make a property less attractive to rats. This requires a certain amount of effort and dedication to ongoing maintenance on the part of the property owner but the labor expended is well worth it.

Rat proof your house by closing off areas of easy access, including small gaps in foundations, roofs and rafter areas. Cover up ventilation openings with rat proof, high strength mesh. Fix or block other non-essential openings in walls, roofs and foundations.

Remove or trim back shrubs and plants that hug the sides of buildings. Rats, depending on the species use these as either a ladder to climb up into a structure or camouflage for burrowing near or into a home or business. Keep lawns closely mowed within 18 inches of the outside walls of structures. Remove woodpiles and debris from yards or move them farther from existing buildings.

Either police your bird feeder and diligently clean up any spillage or locate the feeders away from the house. Seed spillage from feeders is one of the prime attractants for rodents.

Do not feed pets outside of the house, or if you must, monitor the feedings personally and remove any leftover food from the exterior feeding area. Rats love to pillage pet food dishes and water bowls which can also attract other animals like opossums that are also capable of spreading disease to humans.

Do not store pet food in sheds or garages unless you are able to do so in containers that a rat cannot chew through. This means metal, glass, ceramic or heavy duty plastic containers with airtight seals only.

Keep indoor areas clean and free of food and water sources. Clean up food spills immediately and thoroughly. Store food items in chew-proof containers. Keep food preparation areas free of grease; use weak water and bleach solution to sanitize countertops and other areas where food is handled or sits for even small periods of time.

Repair leaky pipes and faucets immediately, avoid areas of standing water inside and adjacent to the house.

Keep homes free of clutter, especially of materials attractive to nest building females. Dispose of paper refuse; keep garbage bins/containers clean and tightly closed between trash pick-ups.

Eliminating the avenues of access for rats forces them to rely on other sources of sustenance and water. Populations will self-control according to natural food sources in the wild. In lean times, rat populations will not increase but decrease; starvation is a natural population control. Females will not breed readily where the amount of available food is unstable or scarce.

With just a little effort, as wells as small investments of time and attention rat infestations can be eliminated in your home.

40 thoughts on “Rat Infestation”

  1. Thanks for all the great advice…I’ve done it all and STILL have a huge problem. I live next door to a “hoarder, a serious hoarder who leaves bags of food out by her front door. I am wondering if her environment has kept the rat population active at my house? They tend to nest under my house where the furnace ducts are (so warm). They make nests from the fiberglass insulation. I’ve had to have pipes rewrapped at considerable expense as well as hiring companies to set traps under there and seal all possible entrances! My question is do you think neighbor hoarder is causing problem? And I wonder if I have any rights re:my rodent infestation. Thanks so much.

    1. I live next door to a woman with tons of bird feed.. Like 20 of them, and we are super clean! We still get these nasty ass rats’!! HELP!!!!!

  2. I live in Gatesville, TX. I am having horrible problems with rats in the home. They are crawling in my children’s cribs (ages 1 yr and one is 2 mths old) They are eating everything the can find. I see them crawling up the fridge and the tables. I have tried to get rid of them but am having no luck. any help is greatly appreciated.


    1. I’m not sure if this will work for you but it has helped me. I’ve sprayed areas of my house down with amonia. About a 75/25 mix 75 amonia. This gives the smell of a predator. Be very liberal with it!!! I also have used Peppermint oil as well. Take Cotten balls and SOAK them with peppermint oil and place them around your home as well. I hope this works for you.

    2. unless u own the home move.

      I knew this family where just nasty ppl.
      they has a huge rat, the more food they got the bigger the rats became. Even though they were not the huge type. The girls slept in different rooms and they owned their home. Apparently they weren’t to concerned even tough they found out that the sores that were constantly appearing, were from rat bites. BC they were not so clean the sores often became infected. They were crawling up under the covers and staying warm and getting pieces of anything they could get for their nests. I refused to go over there but believe it or not they went to the same church.

  3. Help. I think I have a rat or mouse, but suspect rat. My cats food bag has been knawed through and eaten. I need to know how to deal in a way which will not put my beloved cat at risk

  4. We’ve had occasional mouse or shrew but last yr we had a rat & after killing it there weren’t signs of anymore. However this year another 1 appeared several wks ago & I’m a mess. I’m a single mom w/3 kids & terrified of rodents. I have stools everywhere there is a cupboard or sink, 100 rubber balls to throw before entering a rm, 3-4 hrs daily waisted listening for it… just to name a few my crazy behaviors. Are neighbors refuse to buy city garbage bags needed to have your trash picked up so it looked like the city dump til last wk they were made to dispose of it. I almost stepped on a half dead rat last yr so NO POISON THIS YR, sticky traps, all of a sudden in 2 days I’ve caught 5 but not the main 1 still wonders all over, whenever. its not scared anymore. my home is clean, we have a dumpster emptied wkly. Is it that theycould of lived in the trash next door or am I in seripous rat trouble? We are going to a hotel til there gone. My children are 4,5 & 10 so I dont feel I can keep them safe after catching all those. I didnt realize the horror that comes after the catch w/the sticky pads, unbearable sounds n struggle. What else is there I can do?

  5. Hi I actually live right along a green belt and creek in an old part of the city. We have 1 rat that has taken over are home that we cannot seem to kill. We refuse the poisen because when we first bought the house we had one was living in here (was a foreclosure that sat for almost a year) we used the poison and it ended up needing water so desperately it chewed through our dishwasher and refrigerator in just a couple of days of eating the poison. Now we also have a 2 yr old which makes things more difficult as far as trapping. What totally blows my mind is this thing is smart. I woke up to the noise and walked in the kitchen so it darted under the oven. It was the only way back out so it made an attempt as I waited then saw me and ran back under neath I grabbed every sticky trap I’ve had stalked up with I’m talking 8 traps all aligned so it had no way of getting out. That thing got a hold of a ziplock Baggie that had fell I guess behind the stove then used that to get over the sticky trap!! The next morning I see no rat caught but instead a bridge made on the sticky trap to I assume not get trapped is this possible ? Are they that smart? I need to know what I am dealing with here. It nol longer travels cautiously along walls but travels with no fear through the centre of the floors to every room right in front of us while we are still awake ! I feel like I am going to lose my mind: I have chickens too and I know the food blocks attract the vermon from the creek area so I may have to just give them.away after we exterminate these rats and mice. I’m literally getting nautious talking about it. Any help u can give or tips from what I wrote would be fabulous. Email is Brittany.knutson13@icloud.com or Brittany.knutson1028@gmail.com ? = ???????

  6. This is getting bad because my husband thought I was being a drama queen. We caught 2 mice and then I told him I saw a res it took a month to catch just one. I’ve asked him numerous times let’s check for holes because we can keep killing them but they will keep coming. More than food they’re eating out towels and oven gloves. Which I believe is for an expectant mother. We know where they’re running too and I’m 99% sure they’re roof rats. Please help I want to move!

  7. The best way to catch mice or rats is with a sticky trap baited with fried bacon — just a little piece. They cannot resist this. It works every time.

    My issue is rats coming in from outside from behind the baseboard. How can you rat proof behind baseboards in a room?

    1. Sorry Ive had several escape the industrial traps.
      so don’t rely on them. Just saying……….Ive had several come off those I gave up on those

  8. I have a rat in my house it comes and goes no droppings.I have 2 children aged 4 and 2 and I am concerned because rats carry all sorts of disease don’t know what to do please help I am scared. thanks.

  9. Hi can someone help me I’ve got rats or mice not show which 1 but I’ve no seen no dropping the only reason I know I’ve got them as they been chewing bags wot have food in nd been eating my puppy’s food but I’ve got put like strips of poison down and they been taken the whole lot not just having bites out of it I’m really scared can you tell me what it is ?

  10. I have what i consider a serious rat problem in my apartment. Rats are crawling day and night everywhere… I have young kids and its very scary.. What can i do? Im in bronx ny…

  11. I have noticed where the carpeting in my front room corner has been ripped and there is can hole thru the floor. also to the basement ,that door also shows area where somethings ripped at trying to get under it, tearing carpet as well. this activity was notice during early mourning hrs.

  12. I live in the country , and first report hearing something in the walls to my landlord 4 months ago. He did not react. A few weeks later – 3 inch holes in the sheetrock where the stove pipes came in. Then evidence of fecal matter in the pantry. I threw out all bagged, chewable food sources. Called the landlord again. He set out traps.
    Moral of the story is – I took a motel when I saw two rats fighting in my kitchen and noticed fecal matter behind my bed.
    He called an ineffective exterminator, and the problem only escalated. No doubt, they took over even more because I was not present. But I could not stay in a place that was officially classified as uninhabitable by the board of health.
    Suffice to say, my entire place was destroyed. 2 couches chewed to shreds, a bed soaked and molded by urine, mattress, electrical fire ( small and put out ) , and my stored family papers and special items. Horrible. What I do have left is being sanitized. Feces, urine smell on everything. Disgusting and heartbreaking.

    Worst experience ever. If you are unfortunate enough to have this problem – call a PROFESSIONAL IMMEDIATELY. And if your landlord does not do his job – know that you have rights as this is not only a potentially costly and damaging situation, your health is at risk, too.

  13. Hi there,

    I have a mortgage on a house in bradford west yorkshire. We have been having issues with rats getting into my small store room and living room. I don’t understand how they are getting in under the floorboards. I have noticed some drolpings behind washing machine too in the kitchen. We have been putting traps down for the past month and caught 7 so far. All small rats. Now we have been hearing noises in our ceilings over two floors too. They sound like bigger rats. I am at the end of my tether and wondering what is good to use to seal up any holes and extra measures to protect my home? Should i rip ceilings down to see if they getting in from neighbouring properties? Do sonic repellers work? Please help. I have two toddlers too and worried about their safety. Thankyou

    1. To seal up holes I intend to use “Great Stuff”, it worked well for me in previous residences. Rodents don’t like peppermint oil. I am also spraying my baseboards and behind things like my fridge, stove and couch.

  14. Question: I live next to a wetlands area and during the winter rats burrow down along the foundation and access the crawl space. Rat control technician suggested digging a trench along the foundation and filling it with small rocks to discourage the digging. Is this practical advice? Does it have any value in deterring the rodents? In any case, what is an effective counter to the seasonal invasion?

  15. We have a problem, I’m not really sure how it started. We’ve caugh the rat several
    Times and it manages to get off of the traps: glue traps and old fashioned traps.

  16. Please help us!!! I’m not sure what to do and we don’t have too much money but the rat is now no longer running along the base boards and it’s getting off of the traps. Alexandria, Louisians

    1. I use the Tomcat Rat Snap Trap. Put a few m&ms as the bait and gets them every time. I’ve also, very recently, used a mixture of cornmeal, borax acid (powdered laundry enhancer) of equal proportions, with a few sprinkles of cinnamon, m&m’s and dry dog food into the mix. Leave a bowl of water for them to drink.

      The borax acid inflates their stomach with gas. Rats ant pass gas, so their stomachs expandso and kills them everytime.

      I’very left this outside and inside. They have only eaten this mixture inside. I’very found that odd.

      I have also dumped a lot of ammonia in my crawl space. This will burn their eyes and suffocate them. I had to leave the house for a day with three smell of the ammonia. I don’t know if this has worked or not as I did this a few days ago. I can say something was under my bed last night again. Gees! I found ano old boutique bar of soap under my bed that had been gnawed on. I cleaned my bedroom floor with ammonia as well.

      There is also a poison people swear by called ‘One Bite’ available on Ebay or Amazon.

  17. I have been away from my house for two years and now it’s infestered with rats I’ve been told that all the kitchen has to be bunt and ever thing in it has to be destroyed, as the rats are swear rat and have all sorts of disease
    Is there any thing I can do to keep some of my kitchen equipment

  18. We had a big rat infestation so bad we literally had to move out. We used sticky traps to peppermint oil we tried everything.We got rid of our cat and dog so tgat eliminated the problem outside but they decided to chew through our bathroom wall and behind our washer/dryer. I had to tape the cabinets so they couldn’t get in but they always found a way in. Since we moved out of the house i see a few here and there cause there is not food around. I wish someday to move back in they are the worst pest ever!!!!

  19. We bought an electric trap, the rat crawls in and makes contact with metal plates on the floor of the trap. 4 “C” cell batteries, I am on my 14th rat in a week. These cost about $45.00 but worth every penny, I dont even need to look at or touch the rat, just dump in the trash. I do think its time to call a professional, when is it going to stop?

    1. I called orkin to help us deal with our rat problem. All the technician could do was set traps and identify some holes where the rats were possibly coming in. (We had already been setting traps for two months and were aware of the holes.) We wanted the rats gone before we sealed up the holes so they were not sealed inside the house. Be very wary of the exterminator you call and there methods.

  20. I live In a mobil home and the rats
    are under the sink area tearing up the insulation
    just under the flooring. I can hear them at night
    and they wake me up. what is the course of action

  21. I have a bad rat and mice infestation. I hear them in ealls in ceilings. I clean as best I can try not to keep fiid around clean with clorox. And it seems problem gets worse every day. I have 2 small children a 18 monthand 6 yr old. I am scared. We don’t have the money to seal my home. I live next to construction site that surrounds my entire home. And a few pest control have come and has indicated that their property is breeding grounds for rats and mice. I cant sell home I just purchased it last year. I don’t know what to do I need help. Can you help me please.

  22. A welsh man told me that rats are a favourite food for ferrets

    Here in New Zealand ferrets are banned
    But he also said rats won’t go near if they smell ferret urine or poo

    PHONE 808-298-9396

  24. We live in a very rural area of the South Hams and right next to a field and in May saw a brown rat near the bird table. We have a compound where we kept a rabbit and dug a burrow for him, wire enclosed and right by the bird table. Rats have now set up home in there and spread to other areas in our garden. I am a very caring person towards animals and did not wish to poison these creatures, especially as I feed the birds, have squirrels (that I don’t wish to hurt) and a fox and pheasants that visit every day. Apart from this, I have two cats and two dogs, which makes poisoning (which is abhorent to me), something I am fighting against. However, eccentric you may think this is, I don’t wish any animal to suffer!!

    We have a large drive and a big undulating garden and this leads onto a lane and more fields and now we have more rats under an old tree stump by a second bird table at the front.

    I am interested to know what your advice would be ….although I can guess? Kind regards.

  25. I would recommend hiring a professional due to the health hazards that are involved. As mentioned rats urinate everywhere. Both urine and fecal matter may contain Salmonella that can survive on it for over 2 months! Rats are not worth the harm they can do to your body and others, especially if young children are in the home.

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