All Illinois bats are protected under the Wildlife Code (520 ILCS 5/1.1).

Where Do Bats Live in Illinois?

The cave regions of southern Illinois and the valleys of the Mississippi, Illinois River, and Chicago River have ideal natural bat habitats and the highest abundance of bats. Big brown bats, little brown bats, Northern long-eared myotis and tri-colored bats are all colonial bats.

Bat exclusions can be installed when outdoor temperatures exceed 50° F at dusk. Insects are not active at lower temperatures, and all bats in Illinois are insectivores. 

When Can You Remove Bats in Attic in Illinois?

​Between May 15th to August 5th, you cannot get rid of bats from your attic. 

During the spring and summer, females will form maternity colonies in the hollow of trees, attics, or little used buildings. If you find a group of bats in your attic during the spring and summer, tread carefully.

At birth a young bat clings to its mother. When the mother feeds each evening, the young bat is left in the attic. If one were to implement bat removal at this time, the young bats would be stranded inside the attic with no way to feed.

After about three weeks, the young can fly and will start feeding on insects, but they will continue to nurse until they are about 1½ months of age. Once the pups can fly, we can install bat exclusions and a one way valve to get rid of bats in your attic.

Some skill is required to identify all potential entry points because bats can enter through holes as small as 3/8″ (the diameter of a dime) or spaces 3/8″ by 7/8″. 

Bat Removal in Chicago, IL

To get rid of bats in Illinois, you need to use exclusion not exterminator. Bats may not be shot, trapped, transported, or held in confinement except when a bat is found in an area where they may have contact with humans or domestic pets.

Bat Exclusions Restrictions in Illinois

You can remove a bat from your living space any time of the year. A living space is any room in your house that you actively use. If a bat or bat colony is in a non-living space, such as an attic, permanent eviction can only occur from March 15 to May 15 when outdoor temperatures exceed 50° F at dusk, and August 5 through October 30 when outdoor temperatures exceed 50° F at dusk. This guideline is in place to protect pups while they are still unable to fly.

How to Get Rid of Bats

The most effective and humane way to remove bats is by utilizing a bat valve in conjunction with a full home exclusion. A bat valve allows for bats to exit your home but not re-enter. Since each bat removal is unique, our specialist will use or create a bat valve specifically for your home. 

Once the bat valve is installed, all other entry points will be sealed, allowing for bats to exit only through the valve. The removal process typically takes 3-7 days. Our specialist will perform a final attic inspection before removing the valve. After removing the valve, the final entry point will be sealed, leaving your home bat-free.

Bat Removal during the Winter in Illinois

During the winter they usually roost in mines and caves. If natural habitats aren’t available, bats will winter inside buildings. If able, leave the bats alone for the winter and install exclusions once it gets warm. 

They enter a state of bat hibernation called torpor. To survive long periods without a meal, the animals slow their breathing and heart rate to fall into a deep sleep. Unlike true hibernation, bats in this state can wake briefly on warmer days and leave their roost to find meals.

If bats are evicted during one of these warmer months, they won’t have a safe place to return when the temperatures drop again. 

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Sara James profile picture
Sara James
30 October 2026
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Sam did a ton of work on our house when we bought it as a preventative measure against any pests, as the house was not new. We wanted to be sure no mice, bats or other pests could get in. He did all our critter control at our prior house in 2022 so we had him pest proof our next house in 2026. He is the kindest man, knowledgeable and efficient. 100% recommend. You’re buying pest control and peace of mind.
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Peggy Protko
30 October 2026
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I was concerned that there might be squirrels in my attic. Alex did a complete and thorough inspection of the residential premises, and I am happy to report that he found no such evidence. Alex’s service was very thorough and professional, as well as honest. I would not hesitate to recommend your services to others.
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Don Hemmer
30 October 2026
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We interviewed 3 companies to evict the squirrels from our attic. Critter Control was, by far, the least expensive. Their promptness and attention to detail was A+. Brandon from Critter Control provided daily reports about the process. Brandon was the star of the show but we enjoyed working with everyone from Critter Control. Thanks Don and Julie
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Adrienne Numbers
30 October 2026
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Josh was awesome! We had a critter stuck in our fireplace, and he took his time figuring out the best way to handle the situation. He was creative with his solutions, explained what he was going to do, and made sure we understood the process. He was also just a genuinely great person to work with! As a new homeowner, it was nice to have someone who was patient, knowledgeable, and willing to take the time to get the job done right. He never made us feel rushed, and you could tell he really cared about helping us. Critter Control, you have a great employee in Josh! I hope he gets the recognition he deserves because he did an amazing job. I would absolutely recommend Critter Control, and if we ever have another issue, I will definitely be asking for Josh again!
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Shirley Johnson
30 October 2026
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Gave me back "sweet, peace of mind being in my home.
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Katie Coomes
29 October 2026
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Critter Control was very responsive, thorough and finished everything quickly. I appreciate the work of Justin and Steven!
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T James
29 October 2026
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We had a great experience with Luis who helped repair multiple woodpecker holes on our house. He was thorough and professional. Highly recommends him.
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Susanne Abrams
29 October 2026
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Critter Control helped so much with a very difficult pest situation. Throughout the time period , they expertly communicated and scheduled daily service when necessary to get this problem under control. I am so grateful for their kindness and understanding to our specific needs. I will definitely continue to call on them in the future and recommend them to others who are experiencing critter problems.
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Nancy Pippenger
29 October 2026
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Nice job....very personable installers. Answered all my questions!
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Bobby Cox
29 October 2026
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Ashton was a great communicator, quick with his work and very courteous.