You hear scratching above the bedroom ceiling at dusk, or you come downstairs to find a bat looping through your living room. The instinct is to treat it like any other pest problem and call someone to come take care of it. What surprises most Michigan homeowners is that bat removal isn’t simply a matter of scheduling a visit. The timing is controlled by state wildlife law, and acting outside the legal window can trap flightless pups inside a wall void. Creating a far worse problem than the one you started with, and real legal liability on top of it.
We’ve been handling bat control in Grand Rapids and across Michigan since 1996, operating under Michigan DNR license #RC342. Over nearly three decades, the question we hear most often isn’t “how do you get bats out” but “when can you actually do it?” The answer matters more than most people expect.
Michigan’s Legal Windows for Bat Removal
The Michigan DNR identifies a maternity season running roughly from May through mid-August during which bat exclusion work isn’t permitted. This is the period when female bats form maternity colonies, giving birth and raising young that can’t yet fly. A one-way exclusion device installed during these weeks allows adult bats to exit but prevents them from returning, leaving helpless pups to die inside the structure. Beyond being inhumane, that outcome creates a guano and decomposition problem that’s significantly more expensive to remediate than a standard exclusion job.
The legal and practical window for exclusion runs from late August through April. During this period, all young bats are capable of flight, so a one-way exclusion device works as intended: bats exit on their nightly foraging flights and can’t find their way back in. Once the colony has fully vacated, entry points are permanently sealed with durable materials (hardware cloth, metal flashing, or caulk, depending on the gap type). That sealing step is what makes exclusion lasting rather than just a temporary relocation.
One clarification worth making: the exact cutoff date for maternity season appears differently across various sources online, with some stating May through August and others saying June through mid-August. The DNR’s own guidance is the authoritative source, and “mid-August” is the language the department uses. If you’re planning removal work and you’re close to that boundary, contact a licensed Michigan bat removal company before acting.
Why Michigan Protects Bats
Bats in Michigan are protected by state law, and lethal control isn’t permitted under standard circumstances. Michigan is home to nine bat species, five of which are listed as threatened or endangered at the state level. The most significant recent development on the federal side came in November 2022, when the U.S. Fish and Wildlife Service reclassified the northern long-eared bat from threatened to endangered under the Endangered Species Act. White-nose syndrome, a fungal disease caused by Pseudogymnoascus destructans that attacks bats during hibernation, has killed millions of bats across North America and is the primary driver of that reclassification.
The little brown bat and the big brown bat are the species most commonly found roosting in Grand Rapids homes and buildings. Neither is currently federally listed as endangered, but both are protected under Michigan law. Kent County ranked among the counties with the highest number of reported bat roost observations in the Michigan DNR’s 2025 Bat Roost Monitoring Program. That’s not a reason to panic. It’s a reason to understand that what’s living in your attic is more ecologically significant than a typical nuisance pest, which is exactly why the legal framework around removal is as specific as it is.
What to Do If Bats Show Up Before the Window Opens
If you discover bats in your home during the maternity blackout period, you aren’t left with nothing to do. The situation determines what’s appropriate right now versus what has to wait.
Direct Contact with a Person or Pet
This is an immediate health concern, not just a wildlife issue. The Michigan DNR directs homeowners to contact their local health department or a veterinarian right away when direct contact between a bat and a person or pet has occurred. Bats are a primary vector for rabies in Michigan, and the health department will advise on whether post-exposure protocols are needed. Don’t wait for exclusion season to address this.
No Contact, but Bats Confirmed in the Structure
You can’t legally exclude them during the maternity season, but you can schedule an inspection now. A licensed wildlife control operator can identify entry points, assess the colony size, document the scope of any guano contamination, and have a full removal and sealing plan ready to execute the day the legal window opens. That preparation is the difference between acting immediately on August 16th and spending another week figuring out where to start.
Situations That May Qualify for a Permit Exception
The DNR maintains a separate application process for lethal removal permits in situations that meet specific criteria, distinct from standard nuisance-wildlife control permits. These cases are narrow and evaluated individually. If you believe your situation may qualify, a licensed operator can help you determine whether to pursue that application.
How Licensed Exclusion Works in Grand Rapids
Bat exclusion done correctly is a multi-step process, not a single visit. Here’s how we approach it:
- Full inspection: We identify every point where bats are entering and exiting the structure, including secondary entry points that aren’t obvious from the ground.
- One-way device installation: Exclusion devices are placed at active entry points so bats can leave on their nightly flights but can’t return. Secondary points are sealed at this stage.
- Monitoring and final seal: After the colony has vacated, we remove the one-way devices and permanently seal the primary entry points with materials rated for the specific gap type.
- Cleanup and restoration: We address contaminated insulation and guano accumulation. Bat guano can carry Histoplasma capsulatum, the fungus that causes histoplasmosis, so cleanup isn’t optional when a significant colony has been present.
- Ridge-Guard installation: As a certified installer of the Ridge-Guard roof ridge barrier system, we can add a preventive layer at roof ridges, one of the most common re-entry points, that protects against future wildlife intrusion beyond just bats.
Our team includes certified wildlife control operators and certified structural bat management professionals, and Varmint Evictors, Inc. is a member of the National Wildlife Control Operators Association. We don’t use poisons or chemicals at any stage of bat removal. Every exclusion we perform follows the DNR’s guidelines and our own protocols developed over nearly 30 years of Michigan bat work.
Our Warranty & Kent County’s Bat Activity
We back our bat removal and repair work with a warranty that includes a free return visit if bats re-enter after exclusion. The one exception is cabins and cedar shake roofs, where structural movement over time makes a complete guarantee impractical. Outside of those cases, if the work we did isn’t holding, we come back.
Kent County’s ranking among Michigan’s most active bat roost counties isn’t surprising to us. The combination of older housing stock, mature tree canopies, and proximity to waterways that support insect populations makes Grand Rapids and its surrounding neighborhoods genuinely attractive to bat colonies. A structure that’s been cleared and properly sealed is still a potential target if the roofline or ridge cap develops a new gap over time. The Ridge-Guard system and annual monitoring are how we stay ahead of that.
The smartest move at any point in the year is getting an inspection on the calendar so we know exactly what you’re dealing with and can begin exclusion work the day the legal window opens. If you’ve found bats in your home or want an assessment before bat season peaks, reach out to Varmint Evictors, Inc. at (989) 268-7666.