Bats in the attic: why the timing decides what can be done
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By John Stopka, Co-Founder & CEO · Reviewed by John Stopka
Bats are the one animal in this library where the calendar matters more than the method. All bats in Kentucky are protected by state law [1], and there is a stretch of the summer when flightless young are in the roost, so closing the way in traps them inside [1]. Kentucky Fish and Wildlife recommends waiting until after August 15 for that reason [1]. Getting bats out of an attic is an exclusion job done in the right season, not a treatment.
Why are bats different from every other pest in the attic?
Because there is nothing to spray, and because the work has a season.
Kentucky Fish and Wildlife puts it plainly: "All bats in Kentucky are protected by state law, and there are no legal toxicants for bat control." [1]
University of Kentucky's homeowner publication says the same from the other side: "it is against the law to kill any bat in Kentucky unless it is determined the bats are damaging your property," and "nonlethal control methods are recommended" [2].
So the entire job is getting the bats out and keeping them out. University of Kentucky calls that "bat-proofing" the building, and describes it as "the only permanent solution" for problem bats [2].
Is there a time of year when bats can't be excluded?
Yes. This is the part worth knowing.
Kentucky Fish and Wildlife: "Operators cannot adequately deal with bat maternity colonies until after the recommended date of August 15 because there could be flightless young present (from mid-May to mid-August.)" [1]
The reason: "Adult bats exit every night and return to nurse their young. If exclusion methods were fully implemented, flightless young could become trapped inside your house and starve to death." [1]
University of Kentucky's older publication draws the line slightly differently: "Never seal openings from mid-May through July because flightless young may be present" [2]. It calls late November through early March the best time of year to bat-proof a building [2].
The two don't line up exactly. The conservative reading is the state's — nothing that closes a maternity roost before August 15 [1].
What can be done during maternity season, then?
The calendar governs sealing, not looking — and the openings are the part that takes longest to get right. University of Kentucky is blunt about why: you "must find ALL openings larger than 3/8 inch and seal them because bats will continue to use the building as long as they have an entry point" [2].
How do bats get into an attic in the first place?
Through a gap that is already there.
"Bats can enter a hole as small as 3/8 inch in diameter." [2] That is smaller than most people picture, and it is why a roof line that looks sound from the driveway proves nothing.
They also do not make the opening. Bats can't chew new openings, so they use gaps that are already there, like loose flashing, gable vents and spaces along the roof line. University of Kentucky draws the useful conclusion from that: "Because bats cannot gnaw new holes or reopen old ones, once openings are closed they should remain that way." [2]
And "bats return each year to their nursery colony" [2] — a building they have used is one they come back to.
What happens if you just seal the hole?
Two ways it goes wrong, both common.
Seal it at the wrong time of year and flightless young are shut in [1] [2]. University of Kentucky: "Sealing bats inside a building causes the bats to quickly starve" [2]. The problem hasn't gone away; it has become a worse one in the attic.
Seal most of it and nothing changes. Bats keep using a building as long as one entry point remains [2].
What the sources describe is letting the bats leave and sealing behind them, rather than plugging a hole while they are still inside. Done properly, you "avoid trapping bats inside the building and prevent them from returning" — and it has to happen "at the proper time of year by the homeowner or a licensed Wildlife Control Operator" [1].
Kentucky Fish and Wildlife also says: "You should never directly handle the bat." [1]
How does Liberty handle bats in the attic?
Bats are not a plan pest.
Bats aren't part of our pest control plans. Wildlife Control starts with a free wildlife inspection.
Bats are protected by state wildlife law, so all of our bat work follows state wildlife rules.
A local Service Advisor does a thorough inspection to see how bad the problem is, how bats are getting in, like small gaps along roof lines, gable vents and chimneys, and what draws them, like warm, quiet attics and wall voids.
The work then runs in order. We work to get the bats out of your attic or walls, based on where they roost and how they get in. Once the bats are out, we seal the gaps they used, like openings along roof lines, gable vents, chimneys and loose flashing. We point out droppings and stains left behind and explain what cleanup is needed.
After sealing, we come back to check for new activity and check that the sealed gaps are holding.
Attic cleanup and insulation work are handled separately, through Liberty Home Services.
Wildlife control is available in the Paducah area, Southern Illinois and the Hopkinsville area. It is not offered in the Bowling Green area.
When to call a professional
Call when you see bats leaving the roof line, a gable vent or the chimney at dusk, when you hear squeaking or scratching overhead, or when you find the stains that mark a gap bats are using.
Call before you close anything. The season decides what can be done to a roost, and the inspection decides how many openings there actually are — the difference between a job that holds and one that repeats next spring.
Common questions
Are bats protected in Kentucky?
Yes. Kentucky Fish and Wildlife states that all bats in Kentucky are protected by state law and that there are no legal toxicants for bat control [1]. University of Kentucky adds that killing a bat in Kentucky is against the law unless the bats are determined to be damaging your property [2].
When is it too late in the year to get bats out of an attic?
It is the middle of the year that is the problem, not the end of it. Kentucky Fish and Wildlife says flightless young may be present from mid-May to mid-August, and recommends August 15 as the earliest date for dealing with a maternity colony [1]. University of Kentucky calls late November through early March the best window [2].
How small a gap can a bat get through?
University of Kentucky puts it at a hole as small as 3/8 inch in diameter, and says every opening larger than that has to be found and sealed [2].
Will bats come back to the same attic?
They will if the way in is still open. University of Kentucky notes that bats return each year to their nursery colony [2], which is why the openings, not the animals, are what an inspection is really counting.
Are bats covered by a Liberty pest control plan?
No. Bats aren't part of our pest control plans. Wildlife Control starts with a free wildlife inspection, and is offered in the Paducah area, Southern Illinois and the Hopkinsville area.
Sources
- Kentucky Department of Fish and Wildlife Resources. "Bats." https://fw.ky.gov/Wildlife/Pages/Bats-of-Kentucky.aspx (opens in a new tab)
- University of Kentucky Cooperative Extension Service. Thomas G. Barnes. "Bats: Information for Kentucky Homeowners" (FOR-48). https://publications.mgcafe.uky.edu/sites/publications.ca.uky.edu/files/FOR48.pdf (opens in a new tab)