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.

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.
  • Battery-operated rat zapperRat 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.


  1. Ak says

    I have rats under the floorboards. The flooring is sealed and I have closed all acecess points. The problem is they are still under the floorboards and I can hear them at night. Have tried poison and some have died but there seem to be more. Has gonein for months. I have tried everything and am frustarted they are still under the floorboards. Any ideas please?

    • Simon says

      If you can’t catch them, make their lives extremely uncomfortable. Remove all food and nesting material. Use ultrasonic devices, place food outside the area to encourage them to move out.

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