Ever spotted little holes around your house or yard and wondered how chipmunks manage to squeeze through? You’re definitely not the only one. These tiny, clever guys can slip through openings that seem almost impossible.
Chipmunks can get through holes as small as a quarter—about 1 to 1.5 inches wide. That means even the tiniest gaps in your walls or foundation could let them in.
If you know how small a hole they can use, you’ll have a better shot at protecting your home. You might want to check those cracks or holes more closely to stop them from sneaking inside.
This little detail can save you a lot of time and headaches if you’re trying to keep chipmunks out for good.
Whether it’s your attic, crawl space, or garden, chipmunks always seem to find a way in. They’re experts at wiggling through tight spots.
Let’s talk about what size openings to watch for—and how to block these persistent visitors.
Chipmunk Entry Hole Sizes and Physical Abilities
Chipmunks are small and quick, and they can slip through some shockingly tiny holes. If you know the size of holes they use and understand how they move, you’ll have an easier time keeping them out.
Typical Size of Holes Chipmunks Can Fit Through
Most chipmunks can fit through holes about 2 to 3 inches wide. That’s roughly the size of a quarter or maybe a silver dollar.
Holes smaller than this usually stop them, but don’t count on it—sometimes they manage to squeeze through gaps as small as 1.5 inches if they really want to.
When you’re checking your house or garden, look for gaps or holes around this size. Even a crack the size of a quarter might be enough for a determined chipmunk.
Because chipmunks are so flexible, they sometimes squeeze through spaces you’d never expect. It’s honestly impressive, if a little frustrating.
Chipmunk Anatomy and Squeezing Behavior
Chipmunks have slender bodies and flexible bones, so they can slip through narrow openings. Their ribs compress a bit, letting them flatten out and squeeze into tight spots.
They rely on their agility and speed to dart through holes and tunnels. If they feel stuck or threatened, they’re pretty good at backing out fast.
Their small size and soft fur let them crawl into burrows or dens just a few inches across without hurting themselves. This flexibility is why they can get into places that seem totally off-limits.
How to Identify a Chipmunk Hole in Your Yard
Chipmunk holes are usually about 2 to 3 inches wide, smooth, and level with the ground. You won’t see dirt mounds like you do with mole tunnels.
You might notice several entrance holes close together. Sometimes you’ll find plugged or unused holes as chipmunks expand their tunnels.
Look for signs of activity nearby—maybe scattered seed shells or little piles of food near the opening. These holes usually lead to a whole network of tunnels for nesting, storing food, and resting.
If you want more details, here’s a guide on how to identify & fill chipmunk burrows.
Protecting Your Home and Garden from Chipmunks
To keep chipmunks out, you’ll need sturdy materials to block their holes and tunnels. Humane removal is always the way to go if you want to get rid of them without causing harm.
Setting traps the right way catches them safely and keeps things low-stress for everyone.
Recommended Materials for Blocking Chipmunk Entrances
Use hardware cloth with a 1/4-inch mesh size to cover holes and keep chipmunks from squeezing in. It’s tough—chipmunks can’t chew through it.
Fill holes with gravel or coarse sand to make digging a real hassle. When you fill a tunnel, push the gravel in firmly so you’re blocking the whole thing, not just the entrance.
A gravel border around garden beds or sheds can also help stop chipmunks from digging nearby.
Skip things like mothballs—they’re not safe for pets or kids. Instead, seal up small gaps under doors or foundations with metal flashing or concrete to cut down on entry points.
How to Get Rid of Chipmunks Humanely
Try live traps that catch chipmunks without hurting them. Peanut butter mixed with a little fruit works well as bait.
Set traps near tunnels or where you’ve seen chipmunks hanging out. If you catch one, take it at least two miles away and let it go somewhere with food and cover.
Avoid trapping late in the year—chipmunks store food for winter, and moving them then can be risky for their survival.
Natural repellents like cayenne pepper or peppermint oil, sprayed near gardens and tunnels, can help too. These scents keep chipmunks away without any harm.
Best Practices for Setting Chipmunk Traps
Pick a small live trap that actually fits chipmunks. Set up a little ramp so the chipmunk can get inside easily, then sprinkle a trail of seeds leading right into the trap.
Put the trap somewhere chipmunks feel safe—think near bushes or a woodpile. They usually stick close to cover, so don’t just leave it out in the open.
Check your traps often. You really don’t want to stress out a trapped chipmunk by leaving it too long.
If you’re not catching anything, move the trap a bit each day. That way, you’ll have a better shot at finding where they actually travel.
Slip on gloves when you handle the traps. It keeps you safe and helps mask your scent—chipmunks are pretty wary.
When you release a chipmunk, take it far from your yard and let it go near natural shelters. That gives it a real chance to survive.
Want more tips? Take a look at how to fill chipmunk tunnels and find humane removal advice.
