Humane attic bat exclusion in Detroit, with entry points found and sealed, and work timed around the summer maternity season.
Fastest: call (855) 974-4733. Or send this and we call you back.
Bat exclusion in Detroit means finding where bats enter, installing one-way exits so they can leave but not return, and then sealing every gap. Work is usually timed for late summer, after young bats can fly. Detroit Pest Control serves Wayne County, and a technician explains the timing and the price before work begins.
Bats in a house are usually discovered by sound or by a stain: faint squeaking and scratching at dusk, or dark smears and droppings below a small gap in the trim. Bats are not aggressive, and most pose little risk if they are left alone and kept away from people. They can still make a mess, and no one wants a colony living above a bedroom.
The part that surprises most people is timing. In southeast Michigan, bats raise their young in summer colonies, and young bats cannot fly at first. Commercial wildlife sources describe maternity colonies as common from about the third week of May through late July. That is why a good plan is not simply to seal the hole today. A technician looks at the roofline, explains what season it is and tells you when the work can be done properly.
Never touch a bat with bare hands, and never seal a hole while bats may be inside. If anyone has been bitten or scratched, or woke up in a room with a bat, contact a doctor or the local health department right away.
The technician checks gables, soffits, fascia, ridge vents, flashing, chimney edges and siding seams, looking for stains, droppings and the gaps bats actually use.
Droppings and entry signs are checked to confirm the species group, and you are told whether it is the maternity season, which changes what can be done.
All the openings except the main exit are sealed first with durable material, so that bats have one way out and cannot find another way in.
A one-way exit lets bats leave at night but not return. It is left in place for a period of days, with a technician checking that bats are leaving.
Once activity has stopped, the last entry is sealed. You are told about droppings in the attic and insulation, which may need separate cleanup work.
Bat exclusion pricing depends on how many entry points there are, how high they sit, how much sealing material is needed and how many visits the one-way exit stage takes. We do not print dollar figures here, because no honest quote is possible before the roofline is inspected.
| Job | Typical range | What it includes |
|---|---|---|
| Inspection of the roofline and attic | Set by building height and access | a tall house or complex roof takes longer |
| Sealing secondary gaps | Set by the number of openings | older masonry and wood trim often have several |
| One-way exit installation and follow-up | Set by number of exits and visits | depends on how long bats take to leave |
| Final sealing and cleanup advice | Set by access and what is found | attic cleanup may be a separate trade |
These are the factors that move a bat exclusion quote in Wayne County in 2026. Your exact price is confirmed on site before any work starts.
Exclusion is usually timed for after young bats can fly, in late summer. Commercial wildlife sources describe southeast Michigan maternity colonies as common from about the third week of May through late July, and recommend avoiding exclusion during the maternity season, roughly May to mid-August, and not fitting one-way doors in June and July.
That guidance exists because pups that cannot fly would be trapped inside if their mothers were shut out. Those pups would die in the walls and create a smell and a bigger problem. We do not cite a specific legal rule here, because we have not confirmed one from an official Michigan source. Ask the technician for the current timing advice, and check with the Michigan Department of Natural Resources if you want the official position.
For a bat colony seen in June, the practical answer is usually to inspect, plan and wait. Our guide on why bat exclusion timing matters in Michigan explains the reasoning in more detail.
Most bats are not aggressive and avoid people, but they can carry rabies, and a bite or scratch needs medical attention. If a bat has been in a room where someone was sleeping, or if there has been any contact, call a doctor or your local health department and, if possible, do not release the bat.
Never handle a bat with bare hands. If a bat is in the living space, close the interior doors, open an exterior door or window if you can, and keep children and pets out of the room. The health department can advise about testing.
Sealing a hole with bats inside traps them. Adults may find another way into the house, sometimes through the living space, and flightless young can die and cause a smell. One-way exits let the colony leave on its own before the last openings are closed.
Bats can often slip through surprisingly small gaps, which is why a thorough inspection is needed. The technician looks for every candidate gap, not only the one that has staining beneath it, and seals the others first so the exit is the only path.
Bat droppings can be cleaned up, but attic cleanup is often a separate job from exclusion. Dry droppings can stir up dust, so wear a respirator and avoid sweeping if you decide to clean. Heavy deposits and damaged insulation are best handled by someone equipped for it.
The technician tells you how much droppings and staining they see and whether the insulation looks affected. You can then get the cleanup done after the colony has gone, which prevents contamination from returning.
Do not seal anything yourself. Keep a record of where and when you see bats, keep pets away from the area, and keep living space doors closed so a stray bat does not reach bedrooms. Gather questions for the technician, and consider repairing other roofline problems before late summer.
Counting the bats as they leave at dusk over two or three evenings is helpful. It tells the technician how many bats to expect and which gaps they use. Stand back far enough not to disturb the exit, and record the time and weather.
If you are planning roof or siding work this year, tell the contractor about the bats first. Work done during the maternity season can disturb a roost and cause the problems the timing rules are meant to avoid.
After young bats can fly, exclusion can begin with fewer risks to the animals, and it is the standard timing described by wildlife sources for this region. The job is usually completed before the cold sets in so bats are not forced to look for a new home in autumn.
Outside the maternity window, such as in spring or early autumn, a technician can inspect the house and seal gaps that are not in use. This reduces the chance of a colony settling in at all.
A lone bat that has strayed inside is a different situation from a colony. The technician explains how to handle it and what to do about any contact, and then looks at how it got in.
Older Detroit houses have a lot of the features bats like: gable vents, soffit corners, loose flashing, chimney edges and gaps where trim meets brick. The large masonry houses with slate roofs and dormers described in places like Indian Village and Boston-Edison can give bats several possible roof-line entry points, and a house may need more than one gap sealed.
The calendar here is the real local difference. With a cold, snowy winter, southeast Michigan bats are not around all year, and the work window between the maternity season and the cold is limited. A house with a colony found in June may wait until late summer for the actual exclusion, and the technician plans around that so the work is finished before the weather turns.
If you have noticed bats this year, a plan made in spring or late summer is more useful than a call at the last minute. A pre-season inspection also gives you the chance to repair soffits and flashing, which helps against squirrels and raccoons as well.
Most bat exclusion calls are scheduled the same day when a technician is free, and you approve the price before any work starts.
Not sure if you're covered? Check your ZIP code.
Finding how squirrels and raccoons get into Detroit attics, chimneys and soffits, removing them and sealing the entry.
Sealing coal chutes, foundation gaps, sill plates and pipe entries so mice and rats cannot get back into Detroit homes.
Nest removal for paper wasps, yellowjackets and hornets in soffits, porches, wall voids and the ground around Detroit homes.
Bat exclusion in southeast Michigan is usually timed for late summer, after the young can fly.
Usually not by closing them out, because the maternity season is the time when flightless young are in the roost. The technician can inspect, advise and plan the work for later in summer, and tell you what to do about any bat that gets into the living space.
Exclusion is meant to let the bats leave on their own and not return. The method, one-way exits plus sealing, is designed to avoid harming them, and it is why the timing around young matters.
A technician can count bats leaving at dusk, check the amount of droppings and look at the number of entry points. A single bat inside the living space is different from a colony in the attic.
Bats may try to return to a roost they have used before. That is why every gap is sealed with durable material and why the exit stage is monitored. Checking the roofline once a year is a sensible step.
A bat house is an option for people who want bats nearby but not in the attic. It should be placed after the exclusion, and not close to the house. It is not a replacement for sealing the gaps.
Sometimes, though bats are more likely to use roofline gaps and mice use gaps at ground level and utility lines. A full inspection covers both, and our rodent exclusion page explains the lower half of the house.