The two most common bat species in the Chicagoland area are big brown bats and little brown bats. The only real difference is that one is ‘big’ with a 13-to-14-inch wingspan, and the other is ‘little’ with a 9-to-11-inch wingspan. Found statewide, these bats live in attics, trees, barns, under bridges, and caves.

Bats are flying mammals and eat insects. There are no bloodsucking bat species in the Chicagoland area, but they can bite humans, although not intentionally. They are one of the primary carriers of rabies, and if you get bitten, you might not know it because their mouth and teeth are so small. If you find one flying around your house, especially if you wake up in the morning to a bat flying around your home, consult a medical professional immediately.

How do you know if you have bats? 

Bats are mostly active from Spring to Fall and hibernate in the Winter. During this time, you can find droppings in the attic or perimeter of the house. To differentiate if you have a bat problem from a rodent problem, you simply have to look at the droppings. Bat droppings are a little bit bigger than mouse droppings. Also, rodent droppings are smooth, and while bat droppings are coarse. You can potentially hear bats in the attic or actually see them flying in your home.

Bats are looking for cool, dry, dark places to roost. They enter homes around soffits, chimneys, or dormers in gaps that are as small as half-an-inch. Females travel in colonies of 10 or more. Males are typically solitary after they mate.

How do you treat bats? 

At Grizz Pest Management, we treat bats humanely. First, we find the entry points and use exclusion tools to evict them. This can take up to a week as you have to wait for them to leave. Once they do, our exclusion tools prevent them from getting back into your home.

Because of State regulations, treatment for bats can only occur at the end of March to the end of May, then from the beginning of August to the end of October. All of these dates are also temperature-dependent.

Attic overtake 

One night, a homeowner saw a bat flying around in his home. They called Grizz Pest Management, and upon inspection of the attic, Grizz found that the entire floor of the attic was covered in bat droppings.

There was a colony of at least 100 bats mainly living in the peak of the attic. One gap in the home’s soffit was about 20-feet long, which allowed them easy access. Grizz Pest sealed up this gap and added exclusion tools to let all the bats leave. It only took a few days for them to abandon the attic completely.

Once they were gone, Grizz Pest cleaned all the bat droppings in the attic by removing most of the insulation and replacing it with new insulation.