What Size Holes Can Mice Squeeze Through?

Mice are notorious for their ability to seemingly get anywhere. Seriously, mice squeeze into any nook and cranny, and this is why they are so difficult to get rid of. For example, you may have heard that mice can squeeze through spaces as small as 6-7mm. But is this really true and how do you keep mice out of your home?

mouse squeezes through hole

Mice squeeze into anywhere, so be careful!

While mice squeeze easily through small spaces, 6-7mm is a bit of an exaggeration. That’s about the size of a pencil! It’s unlikely that these common rodents can squeeze through such a small space.

So what size holes can mice squeeze through? Generally, they can get through anywhere that is roughly an inch big (25mm). That being said, this isn’t a hard and fast rule. The size of the hole that mice can get through may vary.

For instance, starving mice, that are thinner, can get through smaller holes. Starving mice are also more desperate and willing to squeeze themselves through smaller gaps. Younger, smaller, mice can also get through tinier holes.

In case you’re wondering why mice can get through such tiny holes, the answer is their ribs. These pests have highly flexible rib cages that can move and flatten. This allows mice to get through almost any space, no matter how small.

hole wall

Tips to prevent mice getting through holes

The bottom line is that mice squeeze through small spaces and enter your home, and will often come indoors when it gets cold. This is something that you must be aware of and also take precautions against. What this means is that all holes around the perimeter of your home must be sealed up against mice.

The first place to look is pipes. Electrical, plumbing, and gas lines often have gaps around them. This is where mice are most likely to enter. These gaps can be closed up with putty or other suitable substances. Holes along skirting boards or walls can be blocked up with wire wool.

Also look around the foundations of your home. There could be gaps between your home and the ground. At the same time, check your doors and windows. Mice can also enter through your roof (and make noise in your attic), so look around your rafters, gables, eaves and soffits.


These areas are usually made from wood. If your house is older, there’s a good chance that these are loose, or even rotten. This provides mice with an easy access point. Remember, mice are excellent climbers, and well-able to enter through your roof.

Despite your best attempts, mice may still get into the home. They have sharp teeth and can easily chew through barriers or find another way in. If you are struggling to keep mice out, you are not alone. Call pest control if you need help with this common problem.

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