What Do I Do About Rats Under My House?



We have a rat under our house.  My husband has been under the house to find it.  He found how it/they got in so he fixed that, but the rat has gotten part way into our house.  We live in a manufactured home and our home has what is called a “rat barrier” then the actual floor of the house, so the rat  is between the barrier and the floor.

We have tried the rat traps (use cheese, peanut butter and sardines as bait) and even went the poison route, but still we hear the little invader under our bathroom floor every night around 2:00am.  My husband is obsessed with getting this guy and last weekend he put a hose up through the little hole under the floor and attached the other end to the tailpipe to his truck…I told you he was obsessed.  He ran the truck for about 30 minutes hoping to kill him.

We use to have a little 8 pound dachshund that found a rat in our yard and killed it but she has passed and the dogs we have now only show interest in squirrels. I have noticed our dogs sniffing a lot by the back porch steps…in fact they really sniff all the stairs which is near the entry way(or former entry way) of the rat.  My husband cant figure out if he did away with all the rats points of entries how does he keep getting back in under the house?  Any ideas to get a rat out from between to layers?  We don’t want to have to rip out a big section of under flooring. I need to figure something out before my hubby goes insane.


There is nothing like a rat gnawing at the floor beneath your feet at 2 in the morning to stir up an obsession with rodent control. But first of all, a word of caution about using your truck’s exhaust to kill a rat in your floor.

Anything in your vehicle’s exhaust that can kill a rodent can also kill a human. The carbon dioxide in vehicle exhaust is heavier than air, and will tend to sink into the rat barrier and asphyxiate the rat -if it doesn’t just scurry away- but the carbon monoxide in vehicle exhaust is lighter than air and will tend to rise into your home, where it can poison you. Please, please don’t try to kill rodents with vehicle exhaust!

And if you still had your little Dachshund, or another little dog, or a kitten or a cat, your pet would be at even greater risk of asphyxiation or poisoning than you.

So how DO you get rid of rats underneath the floor? Here are some ideas that actually work, although it may take some experimentation to find out which one works best for you:

  • Place a fan or blower in the crawl space beneath your floor. You probably want a smaller unit, so the noise from the fan does not become as annoying as the noise from the rat. This method is especially useful during the winter. Small animals have to avoid drafts to conserve body heat, and they will avoid any kind of air movement if they can.
  • Place a light in the crawl space beneath your floor. Rats are phototrophic. They prefer the dark, and will avoid lighted areas.
  • Look for burrows leading into your house around your foundation. This can tell you where rats are getting in.
  • Make sure there is no trash or debris against the side of your house. Any kind of clutter gives rodents cover to travel in and out at will.
  • Use a black light to detect rat urine. The average rat urinates 300 times every night. Each drop will show up under black light (much like some other substances that police investigators use black light to detect in crime season investigation). Where you see rat urine, you have rats. You can follow their trail to determine where they are coming in.
  • An alternative to a black light is to use a camera trap. Camera traps allow you to capture the rats in digital pictures or video and are motion activated so you don’t have to watch an empty room for hours. You can read a review about them here.

If you are inclined to use rat poison, it’s important to understand two things. One if that if a rat eats poison and dies, it may not die where you won’t smell it. The downside to killing a rat beneath your house is that you may smell it for several days or a week. But at least you will know it is gone.

The other thing that it is important to understand about using rat poison is that almost all poisons that kill rats will also kill pets and children and make adults very sick if the poison isn’t placed correctly. This means you need to use a poison that the rat can’t spread from place to place, and that you can place so that only the rat comes in contact with it. And you also don’t want your dogs eating a poisoned rat.

If you are sure you can keep both rat poison and poisoned rats away from pets and people, then here are some possibilities I didn’t mention on my site:

  • Water baits. Rats like every other animal need water as well as food. A water bait like Liqui-Tox will attract the rat, and can be placed where pets won’t find it.
  • Tamper-resistant bait stations. These are poison bait containers with openings large enough to let the rat in but small enough to keep pets and people out. If you can’t find a bait station that meets your needs (one that is the right size for your crawl space), then you can make a bait station from a “ball bait” and a length of PVC pipe. Just place the bait in the middle of the pipe. But don’t use loose bait in this kind of set-up.
  • Rat zappers. A battery-operated rat zapper may be just what you need to get your rat. Just be sure to check it regularly. Somehow from your description I get the impression this won’t be a problem.

Mark has a strong background in Engineering and a huge interest in Pest Control as a way of getting rid of rodents and other unwanted pests who can cause a nuisance in your home and garden. You can subscribe to his free daily paper on Pest Control Solutions and follow him on Facebook or Twitter

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  • My cousin used to live on this mobile home and she trashed the place. So we are in the process of cleaning it up. The other night I seen a rat so I put out the rat traps and caught it. Only to find out 2 nights later we were at the mobile home and we saw another rat. It is only one rat at a time being seen. When we are here during the day sometimes we are as quite as a mouse and see nor hear anything. At night time there is only one rat seen and heard. We filled up all the holes of outside entry with bricks. Why is there only one rat?

    • There will be more than one rat, you just haven’t seen them. Make sure you remove all food, water and nesting materials from around your mobile home so hopefully they will not hang around your home for long.

  • Hello mark.I sleep in the bck.of the house near the batbroom.I remembered tbe owner pulling out the floor and standing on the dirt ground in the batbroom.any way THEIR is a little door in my room owner says it connects to the pipes in batbroom.I hear movement in my palstet walls mark and I smell urine.Can I drill a hole in wall and pull them out with ammonia?Or simply drill hole in that little door and put posion?Please help beauty of a home yet the sinch is harming me.

    • Hi Rita - if you are renting, do not drill any holes. Talk with the landlord to work out a solution.

  • Good evening,

    My partner and I have just moved into our newly purchased Victorian terraced half house in SouthEast London. This is our first house purchased together and we are expecting our first child to be born in July.

    During our first week living at the property I was working quietly on my laptop late into the night at a desk in our living room and it became very clear there were noises sounding like gnawing of timber beneath the floor boards in the corner of the room. This repeated 2 or 3 times through the course of the night until it was necessary for me to go to bed.

    I have read through the many posts on this page and am extremely nervous regarding the situation and what my next steps should be, especially with a baby due to arrive very soon.

    I have investigated the exterior of the property and am unable to locate any possible entry points . Fortunately the sounds was very much under the floorboards and there is no evidence of anything entering above the floorboards.

    I’m unsure what the appropriate next steps should be as I do not know where to begin with accessing beneath the floorboards.

    Any advice would be greatly appreciated.



    • Hi John,

      There are no easy solutions, you are going to need to spend time, effort and money to get to the bottom of your problem. To check under the floorboards you have two options. One is to lift the floorboards, if you have traditional floorboards then this is a relatively simple thing to do and you should be able to put them back as you found them. If you don’t have the tools then find a chippy or builder to show you how to do it. The second way is to use an endoscope camera and check for evidence of rats. You might want to get a black light and check for dried urine in your living space to make sure they are not above the floorboards.


  • I am beside myself. My mother has rats. She is 91. I did her way and spent lots to seal up holes with foam by her friend, get an exterminator and put poison under the house. Then she got sick and complained like mad until I paid her friend to get rid of the rats, because she lives in the country and I couldn't get anyone else. she just kept getting more rats and more holes in the floor. She refused to keep the food off her counter, empty her pantry, etc, "because where would she put it". She is a hoarder to a degree with food anyway. She moved the traps the 1st company put in, and put them outside. They told her to stop. She moved them twice. They sprayed some "dust" under the house which was supposed to "irritate the rats eyes". Didn't work. She kept calling them over. They used sticky traps which we already had, and didn't work. I don't think they were very professional in their knowledge, but they cost me a $1000 which they refused to give back, for the month they were there we got more and more rats, even in her box springs!
    Then I hired a man who said to leave the poison boxes he put out for a month. It is 3 weeks. She has put moth balls here and there to protect her precious plants, still leaves food on the counter, but puts moth balls there and on the chairs around her table, where unfortunately they go. They destroyed everything in her pantry but she says it is due to the new guys boxes not working. They are digging through the rat barrier and into the floor everywhere. They are brave now. It has been since November. She still had food on the counter today, (because she keeps her fridge so full she can't put anything in it), and she is shampooing and said she was going to put moth balls around the house. That wont kill them or chase them away because they are still there. I keep asking her to just clean up and do nothing till the pest control man comes this week. He doesn't answer me right now. I hope he will this week. My mother and I fight constantly over the phone and she says "you always are right". I threatened to move her out, (its my house I keep for her, worst deal I ever made, she's always like this when she doesn't get her own way).
    She refuses to leave and got furious when I told her I would move her out till they are gone if this doesn't work. Is she crazy to not leave? Is there anything I do? They keep telling us to patient, but she is not. I understand it is a horrible situation, but it could have been over with much faster if she had listened.
    I hear there is a liquid poison. What about that? I am afraid that the house will be condemned, she will have no place to go, and after paying the last 20 years, I will have to keep paying while it is condemned. I don't have the money to rebuild. Insurance doesn't cover. I will lose everything, she will be furious forever.
    Completely at my wits end. Can you please help? Please?

    Thank you.

    • Hi Ellen - it sounds like your Mother is certainly aggravating the situation by inviting rats into your house by leaving food around. You can tell her that rats find their way around by leaving a scent trail - i.e. urinating over everything including food and kitchen surfaces. However, if she is unwilling to listen to you then you may want to consider bringing in social services and getting them to talk with her. With regards to the rats under the house, if you can easily access the underside of your house then you might want to try and find a rat catcher who uses Jack Russel dogs. I have seen them in action and they are brilliant rat catchers. I'm sorry to hear about your situation and know it can be very distressing. Best wishes.

  • I have a multiple rat problem house I was wondering if I poisoned them will the poison made them super thirsty and cause him to eat to my water lines is this the best way and getting rid of them we have tried trapping them but we're not be as successful.... Sorry for misspelling voice texting

    • Assuming your local bylaws allow you to poison rats then this is a very effective method. Another very effective method is to hire a rat trapper that uses Jack Russel dogs. They will clear your space very quickly. Once they are gone, you need to think about how to stop them returning.

  • I just bought a mobile home and there are pack rats under it in the ductwork. I spent a lot on an exterminator and we trapped one rat. There are others, I know, but we haven't trapped anymore so I have been putting things around the outside to deter them (ie. moth balls, cotton soaked in clove or peppermint oil). I even had an HVAC company come and seal off all of the air exchange vents in the house and create one single new one. I have an awful smell (probably urine) in the house from the urine that was in all of the ducts that were closed up. I had hoped closing them off would get rid of the smell but it didn't. I don't know what to do now - I am even considering trying to sell the place despite only living her a month. I can't take it! How can I get rid of this awful odor that's in the sealed off ducts? I probably shouldn't have sealed them off and just had them cleaned out but that's too late now. Please help!!

    • Hi Janet - have you tried something like "Urine Off" - the problem is I don't know how you will get it down the ductwork.

  • Do you think peppermint oil is a good deterrent?

    Also, I saw a woman (You Tube video) pouring Ammonia on rags and stuffing them in areas in her garage.

    Is that a good option to put under the house in the crawl space?

    I want them GONE and then Ill tackle the issue of clean up and fixing the insulation.

    • It won't have much of an effect. However, do use as many traps and deterrents as possible - you want to use overwhelming force! How will you know when they have gone?

      • I agree. I use peppermint, moth balls, rat traps, many other sprays. I still get rat problema once in a while and it take a lot of repellant /deterrent to keep these pests away. I noticed that this only happens during winter.

  • I need help. Rats have broken through the screens that lead underneath my house. How do I replace the screens without trapping them inside? I think they’ve made their way into my walls and attic. My dog has been going crazy at night because she hears them, I hear them too! I just want to be able to sleep normal again without worrying about these rodents.

    • You have to catch them. Mine eventually died under the floor and we had to wear masks in the kitchen for months. I made the mistake of touching the traps. You have to use newspaper to touch traps and have no trace of human contact.
      I had every trap on the market - even the electric zapper ones and I didn't catch it.

      However, an electrician found a 13 inch mummified one behind a skirting - which was from another rat invasion many years ago. This rat had secreted itself between a heating pipe and skirting. I only remember an infestation of black flies and could never find the source.

      Be patient and catch the rats. Believe me: you do not want them to die.

      Having said that: the best poison is the mice and rat poison that comes in these "pasta" sacks. It's not in the rat section at Homebase. It's ultimately what killed mine. All the others do not work

    • That's a good question. You can repair the screens and put a one-way door or a one-way door cage trap built into the screen.

  • Are peanuts and apples with peanut butter enough to entice a Norway rat to a large victor trap. I have caught 6 with peanut butter alone and traps, but they seem less desperate for food than before. There are new holes channeling under the house, rental at that, and under the deck in the back yard. Is this a sign to high tail it out of here?

    • I would tell your landlord about the rat problem because I would have thought they have an interest in maintaining the properties integrity. With regards to bait, I wouldn't get over complicated with it. You could try different bait in different traps, try putting out more traps and try nesting materials as bait.

  • Hi, I have a Jack Russell. She is constantly sniffing the drain lid outside of the house. She then started sniffing around the skirting board in the hallway, there was a very small gap and my husband filled it. She is now sniffing around the kitchen area towards the underground area which is around 6ft deep! I have had some building work done. The only way to get to this area is to take the flooring up! The council has dealt with any rats that were under my garden shed as the dog has also been digging there! Should I phone them?

    • The council will only put down poison. Your best deterrent and defence is your Jack Russell. I was on this forum 6 months ago with a rat under my kitchen floor. I tried every trap on the market to catch it. I ended up using poison after it ate through the BT cables, the Alarm and the Intercom, oh and a mains wire.

      Oh and 3 oak kick boards in the kitchen.

      I used the poison which is in the pasta bags from B&Q meant for mice and rats.

      It was a huge mistake. The smell was so horrendous my son and I had to wear masks in the flat. It still lingers. Then when I was getting the alarm cable repaired, the guy found a mummified rat 13 inches long trapped in a cupboard behind the skirting board. It died many years ago when we had another rat infections.

      Please persevere. Do not kill the creature. You have to try and catch it/them. However, whilst your dog is around they will not come out.

      Best wishes

    • Theresa

      Yes I believe you should, but you may need to gather a little evidence for them, try to identify some rat droppings.


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