My mouse found a way to get out by using her head and body to force the bars further apart and then escape through the gap. She has been doing this for the past two days.

How do I make her stop or not let her get out?

She can get out fairly easily now and she does it at night, forcing me to wake up at 6 a.m. and ask questions like these on Stack Exchange.

  • 6
    Can you provide more information about the cage you mouse is in? Picture of cage would be helpful. Commented Jun 22, 2014 at 4:55
  • 2
    As Psych says, a picture would be most useful. It might be that you'll need to modify your cage, possibly by adding a horizontal reinforcing bar at an appropriate level, or it might be that you need to replace the cage, in which case you might consider whether the one you have was chosen poorly or, at an extreme, possibly mis-sold as "unfit for purpose".
    – ClickRick
    Commented Jun 22, 2014 at 8:38

3 Answers 3


Mice are known to be capable of getting through 1/4 inch wide gaps. You will have to change your cage to something more escape-proof. Without knowing what your cage looks like, I must assume your cage only has vertical bars. You have 2 options:

  1. Keep the mouse in a cage with vertical AND horizontal bars (crossbars). The problem here is that the mouse may still escape if the resulting gaps are not small enough, and you will need to buy a new cage; retro-fitting your existing cage will be too much effort, and mice are excellent at circumventing repairs.
  2. Do what I did when I had mice: I kept them in a glass-walled aquarium. It works for the pet stores, and it should work fine for you.
  • Wouldn't humidity be a problem in a less "breathable" cage like glass? Commented Jun 26, 2014 at 1:26
  • @starsplusplus - I never had a problem; granted to my memory I either did not use a lid, or the lid I used was a rectangular screen. Humidity was not a factor.
    – JoshDM
    Commented Jun 26, 2014 at 1:41
  • 1
    One of the reasons I was taught not to use glass aquariums for guinea pigs (besides size, which would be different for a mouse) is that the ammonia from their urine can build up and be hazardous to breathe. I'd guess that housing a mouse in an aquarium should require the owner to be extra diligent about cleaning the cage.
    – Zaralynda
    Commented Jun 26, 2014 at 12:57
  • @Zaralynda - I used a completely air-permeable wire mesh lid, and I cleaned my aquarium a lot; it does work for pet stores. Also, you could point a fan at the lid (but not point the entire fan into the cage) to aid air circulation.
    – JoshDM
    Commented Sep 8, 2015 at 16:51

I think you've got a few options here. One is like JoshDM suggested and get a 10gal glass fish tank. You can get a wire lid if there is anything she can stand on to get out. However, I wouldn't add much to it if it's just a temp cage till you find a better solution.

Another temporary solution that may or may not work, depending on how determined your mouse is, is to buy hardware cloth or metal porch screening at a hardware store. The hardware cloth is metal screening and the gaps come in various sizes. The issues with either of these are that they don't look good and if you just cut a 4-inch strip and ran it around the bottom perimeter of the wire cage, then it would block her, but she might be able to climb above it and squeeze through higher up.

An option that would look better and be more functional is if you were to get one of the plastic cages with all the tunnels and towers and stuff. Not only would she have a lot of things to play with, but it looks good too. Downsides with are that a lot of people think the air flow isn't good enough. Also, they do chew and scratch on them, so they do start to look worse over time. I never had an issue with my hamster in one and I even had it rigged so she could get in a wire cage and she spent as much time in one as the other.

A last option is building one yourself. This will be more expensive, but you could end up liking it much better. Below is one example of many different 'homemade hamster cages', which is what I put in google to find all the pictures.

enter image description here

I chose that one because I know there is an instructional video I watched on youtube.com for how to make it. You can have a nice, clear acrylic front and you can have a completely open top. You can also screen any combination of the top and sides to allow breath ability. It's just what's in your imagination. You can make a super artistic cage that looks like professional furniture if you want.

I don't have any idea of when I'll get another hamster/mouse/gerbil, but when I do, I'm going to build my take on a cage I once saw. It was roughly 2'x4'x5'. It had several levels with tubing so the animal can go between each level. I want to make each level easily removable for easy cleaning. I'll also have slots with screen for ventilation and to make sure the ventilation is good, I'll wire up a small computer fan to push air to each level. I will have light on each level and a different set up. For instance, one level is a feeding level, one level has toys, each level has water, etc... I even want to the top level to have dirt and real grass, though I don't know how long I'll want to clip grass with scissors if they don't eat it down. I'll also have a sand pit for them to roll in. It's just some ideas of what you can do. For now, you could get a Rubbermaid container pretty cheap and drill a bunch of 1/4" or slightly smaller holes up near the top. You could even leave the top off, but it needs to be fairly tall, as mice can jump well. You don't want the holes low as they will bore them out and escape through them. It'll be a good temporary home. You can get a clear-ish one, and since you can get a large one cheaply, there should be plenty of air volume to make ammonia a non-issue till you get a solid cage built.


Never leave any container for mice without a lid! They are not like hamsters. A mouse can run up the side of a metal filing cabinet in seconds. Any cage lid should be reinforced with 1/4 inch hardware cloth. Mine chewed through the metal of a tank lid, but we have yet had one chew through much thinner hardware cloth. I don't know why that is.

Hardware cloth does not bend well. It will start to break after a while, so keep an eye on it and replace it now and then.

The hardest part about keeping mice is keeping mice!

  • This question is 8 years old and as such your answer is of no use to OP assuming that they no longer keep mice. Even if they do still keep mice, 8 years is plenty of time to find a worthy solution. However, I will say that this answer may be of use to future readers. Commented Mar 9, 2023 at 20:58

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