What Animal Is in My Attic? How to Tell If It's Bats

Faint scratching or squeaking high in your attic usually means bats — loudest at dusk and dawn, quiet in between. Heavy thumps at night point to raccoons. Fast scurrying by day means squirrels. Tiny scratching low in the walls suggests mice. Timing, sound, and droppings tell them apart. Here’s how.

Wondering what animal is in your attic? Noises in the attic at night are unsettling, especially in the dark. The good news is that you can usually figure out what’s up there without ever climbing into the attic. Four clues do most of the work: when you hear it, what it sounds like, the droppings you find, and the size of the gap the animal used to get in. Let’s walk through each one, bat-first.

What animal is in my attic? Start with the timing

Timing is the fastest filter, because the animals that move into Ontario attics keep very different schedules.

Bats and raccoons are nocturnal. Squirrels are diurnal — active in daylight. Mice run mostly at night but will move any time it’s quiet. So before you worry about the exact sound, ask yourself one question: when is it loudest?

• Only at dusk and dawn, then quiet: most likely bats.
• Loud at night, heavy and slow: most likely raccoons.
• Loudest in the morning and late afternoon, in daylight: most likely squirrels.
• On and off all night, sometimes during the day: most likely mice.

That single question rules out half the suspects before you’ve done anything else.

The quick sound-and-timing table

Here’s the full comparison at a glance.

Animal	When you hear it	What it sounds like	Where in the house	Smallest entry gap
Bats	Dusk and dawn; silent mid-night	Faint fluttering, light scratching, thin high squeaks	High up — attic peak, soffits, wall cavities near the roofline	About ½ inch
Raccoons	Night	Heavy thumping, dragging, chittering, “crying” kits	Attic, chimney	4+ inches (tears openings wider)
Squirrels	Daytime — morning and late afternoon	Fast scampering, rolling nuts, gnawing	Attic floor, along the roofline	About 1½ inches
Mice	Through the night, some daytime	Tiny scratching, faint scurrying, gnawing	Low in walls, behind cabinets	About ¼ inch

Does it sound like bats?

Bat sounds are subtle — you usually have to be in a quiet bedroom just below or beside the roost to catch them. The most reliable is a soft fluttering and scrabbling as the colony stirs and exits around 30 minutes after sunset, reversing before sunrise. You may also hear light scratching as bats shift inside a wall cavity, and thin, fast, high-pitched squeaks — especially during summer, when pups call to their mothers. What you will not hear from bats is steady gnawing or heavy thumping. For the full breakdown of every sound and how to tell it from rodents, see our guide to bat sounds in the walls and attic at night.

What do the droppings tell you?

If you can safely spot droppings — often on insulation, in a soffit, or on the ground below a gap — they’re one of the best confirmations.

Bat guano is small and dark, and because a bat’s diet is almost pure insect, a dry pellet crumbles to a shiny, glittery dust when pressed. It also collects in a concentrated pile directly under one spot, since bats reuse the same roost and exit nightly. Mouse droppings are a similar size but hard and scattered. Squirrel droppings are larger and cylindrical. Raccoon droppings are large and tubular, left in a latrine. Our bat droppings identification guide shows exactly what to look for.

One safety note: don’t sweep or handle a dry guano pile bare-handed. Disturbing old droppings can release spores linked to a lung concern called histoplasmosis — we cover the precautions in histoplasmosis from bat guano: risks and prevention.

How big is the entry gap?

The size of the hole is a giveaway. Bats need only about half an inch — about the width of a pencil — which is why they slip in where larger animals can’t. Look for a neat gap at a soffit corner, roofline, gable vent, or chimney flashing, often ringed with dark, oily staining from bat fur. A big torn or freshly chewed hole points to a raccoon or squirrel instead. Because the gaps are so small and so easy to miss, sealing a home against bats is exacting work — our complete bat-proofing guide walks through it at the half-inch level. (Curious which species you’re hosting? Ontario homes usually have one of two — see big brown vs little brown bats.)

What if it’s not bats?

If the clues point somewhere else, you’re still in good hands. Bats and Wildlife handles the rest of Ontario’s small wildlife too, with the same humane, seal-it-for-good approach we use for bats. Here’s where to go next:

• Heavy night thumps, chittering, or crying kits → raccoons. See our humane raccoon removal guide.
• Daytime scampering and gnawing → squirrels. See squirrels in your attic. Fast scampering and gnawing at night — not the faint dusk-and-dawn pattern of bats — can also be flying squirrels, which are still a squirrel job.
• Rustling or a musky smell low under a deck, porch, or shed → skunks. Skunks and other ground-denning wildlife are covered on our wildlife removal page.
• Tiny, steady scratching low in the walls → mice. Mice and rats are the one job we don’t take — they’re work for a local rodent specialist, not a bat or wildlife crew.

Whatever’s up there, the timing-sound-droppings-gap checks above will point you to the right answer.

What to do if it is bats

If the timing, sound, droppings, and gap size all point to bats, here’s the plan.

Don’t try to seal the entry yourself, and don’t disturb the roost. No banging on walls, no sprays, no ultrasonic gadgets — none of it drives bats out, and it can push them from the attic into your living space. Sealing a gap without a one-way device also traps bats inside the wall, where they perish and the smell seeps through the ceiling.

Mind the calendar. In Ontario, May through early August is maternity season — flightless pups are in the roost, so exclusion isn’t done then (it’s also against provincial law to trap them inside). The practical exclusion window runs mid-August through October. If you’re calling during maternity season, the right move is to book the inspection now and hold your spot for the moment the window opens. Our post on why maternity-season timing matters explains the detail.

Book a free inspection. A specialist walks the whole exterior, finds every entry point (most homes have several), installs one-way devices so the resident bats leave on their own, and seals the building for good once the last one is out. That’s the humane, permanent fix — the full process is in our complete guide to humane bat removal in Ontario, and you can read what the work involves on our bat removal and exclusion service page.

After a full inspection you get a clear quote up front, with no pressure to book. And every exclusion we do is backed by our Lifetime Warranty:

If a bat re-enters through any point we sealed, we come back and do all the work necessary — at no extra cost. Forever.

Better still, that warranty is transferable to new owners if you ever sell the home — a genuine asset to hand along.

When to call

If the noises overhead line up with bats — faint sounds at dusk and dawn, crumbly dark droppings piled under a half-inch gap — the next step is a free, no-obligation inspection. We serve homes across Grey Bruce Simcoe and Huron, and we’ll tell you exactly what your home needs. Two related reads before you call: if you’ve also seen a bat inside recently, check what to do the night you find a bat in your attic and, if anyone may have had contact with it, do bats carry rabies in Ontario. And if a colony has left a heavy build-up behind, our attic guano cleanup and decontamination guide covers the rest. Request an inspection from our bat removal and exclusion service page or the home page, and we’ll get back to you quickly.