How to Tell If You Have Bats in Your Attic (and What to Do About It)

If you’ve been hearing strange fluttering or squeaking sounds at night, there’s a good chance you might have bats in your attic. While bats play an important role in controlling mosquito populations, they don’t belong inside your home. Not only can they damage insulation and create strong odors, but they may also pose health risks through droppings (guano). The good news? With the right approach, you can protect your home while also respecting wildlife.

Signs You May Have Bats in Your Attic

1. Chirping or Scratching Sounds at Night

Bats are nocturnal, so activity is often noticed after dark. If you hear high-pitched squeaks or the sound of tiny wings, it could be bats moving around your attic.

2. Guano (Bat Droppings)

One of the clearest signs is bat droppings. These often pile up near entry points like vents, chimneys, or eaves. Unlike rodent droppings, guano is crumbly and shiny because of insect wings inside.

3. Stains or Grease Marks Near Openings

As bats squeeze in and out of small cracks, their bodies leave behind dark, greasy stains around the entry point.

4. A Strong, Musky Odor

Guano and urine can quickly create a powerful smell that seeps through insulation and drywall.

5. Seeing Bats at Dusk

If you notice bats flying out from your roofline at sunset, they may be roosting in your attic during the day.

Why You Shouldn’t Handle Bats Yourself

While it may be tempting to try and block off entry points or remove bats on your own, this can be unsafe. Bats can carry rabies, and improper exclusion methods can trap them inside your attic or separate baby bats from their mothers. In Massachusetts, bats are a protected species, and humane removal is the only legal option.