An adult squirrel can squeeze through a hole the size of a US quarter — about 1 inch in diameter. Eastern grey squirrels, the most common attic invader in the Louisville area, comfortably fit through openings around 1.5 inches wide, and juveniles can slip through even smaller gaps.
Even if a gap looks too tight, it usually isn't safe. Squirrels are rodents, which means their front teeth never stop growing — and they can chew through wood fascia, vinyl siding, aluminum flashing, and shingles. A crack the width of a pencil can become a full entry hole in a single afternoon of chewing. That's why simply blocking the hole almost never works, and why squirrel chewing damage tends to get worse the longer it's ignored.
First, don't seal it while a squirrel may still be inside — a trapped squirrel will destroy wiring, ductwork, and drywall trying to get out (or die in a wall void). The correct fix is a one-way exclusion door followed by chew-proof repairs in steel and metal. You can read about how exclusion works or see our guide on preventing squirrels before they find an opening.
If you're in the Louisville metro and hear activity overhead, our team provides professional squirrel removal in Louisville with a full-property inspection that identifies every quarter-sized gap — including the ones you can't see from the ground — and seals them with a lifetime warranty.
Our squirrel exclusion service seals every vulnerability in chew-proof steel, backed by a lifetime warranty. Serving Louisville, KY and Southern Indiana.
