Deer mice are very small, not much over 6-7 inches, including the tail.

Thank you for responding, rhizo! Was beginning to think no one read these forums anymore.These might have been 6-7". I didn't measure the one that left whole at 3am.

The mice I've always seen before are tiny compared to these creatures. What I'm used to is the grayish mice that seem flat enough to go through 1/4" openings. Would not surprise me to learn there are tiny openings somewhere in my house. What concerns me is not what kind of mouse it is, but how is it moving in and out of my house (if it is), and what is it eating? Not people food, nor any pet food.

The mice may not be eating anything in your house, but just using it for warmth for the winter. I've noticed that we get an influx of mice into our house as the weather turns cold each late autumn. Also, mice will snack on the smallest of crumbs, so even a pizza box left on the counter offers a generous meal for them. Unfortunately, Deer Mice are the one type of mice that can carry diseases that can infect humans. So, we really need to limit their numbers in our homes. The best solution is routine, humane trapping. In my opinion that means fast and lethal traditional snap traps baited with peanut butter. I feel that poisons are too dangerous to pets and children, and I'd rather not have dead mice decaying in my walls. Good luck.

Martha

I feel your pain. We're learning that mice can get in just about anywhere at all. In the past year or 2, they've gotten into our crawl space via cracks in the mortar of our outside brick chimney, in through small (and large) tears in the netting in the foundation vents, going under the 4' foundation walls, coming in around any pipe/tube that comes in through the foundation walls that aren't completely sealed off. We were able to keep them from getting from our crawl space into our small basement, fortunately, but they are still getting into the crawlspace intermittently.

We even had one stuck above the fan filter over our stove!

We set traps right inside the crawlspace. (we have a small door that opens from our small basement into the crawl space). Fortunately, very few have gotten into our house recently. When we discovered they were coming in from the cracks in the chimney and hubby sealed them, they all came into the house.......the oven, the kitchen cabinets, etc.,etc. It was awful.

One place they got into our house was through a small opening in the trap door that was in the closet, to access the bathroom shower plumbing. They could also squeeze under the door to the basement. I sealed the trap door, and I got one of those rubber door sweeps and put it on the bottom of the basement door.

Once we heard louder chewing in the walls, so I got a rat trap. Turns out it was a red squirrel :(

We discovered that it came in through the screen on the foundation vent. Hubby has spent hours in that horrible place (the crawl space..........and we have a pretty nice one compared to some!) and he's tried to close up every possible tiny hole.......but you just can't seal up everything. Do what you can, and set traps. And like was said, definitely do not use poison. Besides hurting pets and children, if they die outside after eating the poison, then anything that eats the dead mouse will be poisoned too.

They could be bringing their own food with them. Hubby found a bunch of seeds in a nest in the crawl space that had to have been brought in from outside.

I was out in our chicken coop the other night. I've kept the small chicken door closed because of the horrible cold. I saw a small black mouse run to that closed door, and disappear through a crack I couldn't even see! They are definitely a challenge. Good luck!

I've got to get a picture of one of these. Tigger caught another one last night! All I got to see of it was the rear end sticking out her mouth. These things are as big as a chipmunk, I swear. Not including the tail!