This may seem like a silly question, but...

The scenario is that I'm adding a bit of storage underneath the bottom half of our stairs. Up until now it was just a closed in space that was being wasted.

So I pulled off the sheetrock and found a deserted mouse metropolis. LOADS of fiberglass insulation chunks mixed with a huge amount of seeds, mouse poison and mouse poop.


Shop-vacced it all out, bleached every surface, sprayed it down with animal-pee descenter and went to work figuring it out.

Turns out the contractors were incredibly lazy in their hole cutting in the subfloor. There was huge gaps around the vent pipe and the electrical wiring that went down into the crawl space.

I went and got some rodent-proof great stuff and spray foamed all the openings and now it's all clean.

The question:

Before I close it all back (I'm adding some built in drawers in the front), should I toss in some mouse poison pellets? Is that a smart 'plan b' in case they get back up in there somehow, or is that only going to encourage them to get back up there because the poison attracts them?

  • 1
    If it didn't, I'm not sure what good it would do.
    – Comintern
    Commented May 3, 2015 at 0:13
  • 1
    @Comintern well, you usually place it in places you know the mice already are.
    – DA01
    Commented May 3, 2015 at 0:34
  • 2
    Right, but think about it this way - why would there be mouse poison already in that wall? The (former) mice considered it a food source, so they took it there. I'd think the only difference between putting mouse poison and a box of cereal in the wall is the the former will kill them, the latter won't.
    – Comintern
    Commented May 3, 2015 at 0:38
  • 2
    I would avoid putting a "food source" somewhere that the mice aren't. keep in mind that it's also called "bait" and that implies it's desirable to the mice. e.g. they'll smell it and try and get to it.
    – William S.
    Commented May 3, 2015 at 0:56
  • @comintern that's a good point. I thought maybe the poison was there originally, but the mice transporting it there makes a lot more sense.
    – DA01
    Commented May 3, 2015 at 2:12

2 Answers 2


No you shouldn't.

If you put animal bait there, a stray rodent might find its way in there and perhaps die, which would cause a stinky problem after a few days. If you did a sufficient job sealing up the area with spray foam, the problem shouldn't come back!


For 23 years I've been doing rodent work in the DFW area. From houses to the major sports venues, I've learned some things. Some were taught to me. Other things I have learned on my own. Here are some helpful hints.

Never put out poison in a structure where people frequent, work, or live. If you do, two things are likely to happen. The next animal that finds it will likely die as the previous answer has said. Or, the bait will get old and grain beetles will hatch from it, and they will be your next pest problem.

Some people will try to convince you that some bait will make the rodent thirsty and they will leave to get water. Or, use this bait and they will die and not stink. Don't you believe it!

Locate entry points and do not seal last one until all rodents are eliminated from structure. If you do not find all the entry points, the problem will reoccur. If you seal them in, they will risk death to get out. But more likely they will chew through a wall or the ceiling and then the fun begins.

Mice will nibble on several different foods. Peanut butter as bait works but mice love cocoa products better so Snickers is my proffered bait of choice. Mice are stupid and will go back to trap even if trap has missed before. My record trapping time for a mouse using an old fashion snap trap is 40 seconds after I shut the office door. If bait on a snap trap is gone and the trap is still set, insects such as ants or roaches ate it. If you caught a mouse and the bait is gone, there is another mouse. Remember, the early bird gets the worm, but the second mouse gets the cheese!

Rats are somewhat intelligent. If you do not set a trap correctly and it missed, the rat is likely to never to go near it again. If deprived of water they will chew through a water line. Rats drink about an ounce of water every day. Leaving uneaten dog or cat food outside or inside is setting up a buffet for rodents. Extremely good climbers with exceptional balance and run the small power lines from poles to structures. Rats have poor eye site but can navigate in total darkness. They also have an excellent sense of smell. A dead rat in an attic or wall will smell for up to three weeks unless removed. The sooner you look for it, the better the chance of locating it. The odor tends to sink so if dead one is in a wall smell will be strong at baseboard. If it died in the attic under the insulation, you may not smell it until you remove the insulation right above it.

If you can find a dead rodent and remove it, you can try a product called X-O Odor Neutralizer. Apply directly on spot. Your local hardware store may have it.

Happy hunting

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