A Bat in the House in Michigan: What to Do First

What should you do first?

The order follows the health agencies: the open window comes last, once the health department has ruled out contact. The National Park Service treats a possible rabies exposure as a medical urgency, so make the call quickly.

Contact is not always obvious. The CDC says bat bites can be tiny and you may not even know you were bitten. In Michigan, MDHHS reports, bats are the animal most often found with rabies.

How does rabies testing of a bat work in Michigan?

Through your health department or animal control, depending on the county. The CDC says to contact animal control or your health department to safely capture a bat found in the home for rabies testing. Jackson County names its animal shelter, as well as its health department, for arranging testing, and Kalamazoo County’s Animal Services & Enforcement retrieves a bat that is acting as if it has rabies. In some counties the health department decides whether the bat is tested: Washtenaw County says it must approve any animal before it is tested for rabies, and Kent County tests a bat only when its staff find a possible risk to a person, then calls with the result and with instructions if treatment is needed.

Do not touch the bat: the CDC says to avoid touching bats, and USFWS says never to touch one with bare hands. If it has to be confined, the first USFWS step is to close it into one room or area, away from children and pets. The health department can tell you how to capture it, and some counties publish their own steps, listed by county.

Which health department do you call?

The one that serves your address. Wayne County says Detroit runs a public health department of its own, separate from the county’s. The City of Lansing lies in Ingham, Eaton and Clinton counties, by the 2020 Census, and each part has its own department: the Ingham County Health Department; the Barry-Eaton District Health Department, which serves Barry and Eaton counties; and the Mid-Michigan District Health Department, which serves Clinton, Gratiot and Montcalm counties. Part of East Lansing is in Clinton County too. The health department lookup gives each department’s own bat steps where it publishes them, every number with what it is for, and the page it came from.

Does one bat inside mean there are more in the attic?

It is worth checking. A single bat can come in by chance: USFWS says bats often fly in through an open door on evenings when an outdoor or garage light is drawing insects. It can also come from a colony. USFWS says little brown bat maternity colonies are commonly in warm sites in buildings, like attics, and that large groups of bats in warm months are almost always pregnant and nursing females that return to the same colony year after year.

Signs that bats are using the house, from the U.S. Forest Service’s guidance on bats in buildings: droppings or insect parts under the eaves or on a porch, dark stains on walls and near ceilings, and sounds from the bats. The CDC says watching where bats exit at dusk may show how they are getting inside.

If there is a colony, the next steps are on the bat removal and exclusion page, including the maternity season, typically May 15 to August 15 according to USFWS, when exclusion should never happen.

Why a summer colony has to wait is explained in the guide to Michigan’s bats.