Explaining Check Valves for Bats

Let’s say you hypothetically noticed a bat or two in your home over the winter and called Northern Pest in the late spring to set up an inspection. Your technician arrives in early June, and writes up a quote, which you consider for a week or so. You decide to move forward with the bat eviction, and call to schedule the work to be done, only to be told that we need to hold off on installing your check valves (the one-way doors used to evict bats) until mid-August. Why is that?

The reason is because up until that time, any juvenile bats that might be in your attic are still unable to fly on their own. They will starve to death if their mother exits the den to feed and is unable to return due to the check valves and seal work we would have completed. However, a couple weeks into August, the juvenile bats that have been maturing all season are finally ready to spread their wings and move out of the house – literally.

This can present another problem, which is why most of our calls for bats inside peoples’ homes come between late July and early August. Juvenile bats, like children, are a bit clumsy, and can end up in odd places. Open windows, chimney flues, and furnace exhaust pipes are just a few examples of areas a young bat might try to enter. It is also common for a juvenile bat from one colony to enter an entirely different home through a gap in a soffit, or underneath a ridge vent, and get into a new attic space.

Once inside the attic, a young bat may not realize how to get back out and end up within the living space of your home. This happens through cold air returns, recessed lights, and open wall voids leading to the basement. Understandably, a bat within the home is distressing to people and many customers have called for a singular sighting of one.

To minimize the risk of waking up to a bat in your bedroom, the best time of year to complete bat-work is between April and June. If you need to wait until after August, try to get something done before the first constant frost (usually early November), as an overwintering colony in your attic has the possibility of a torpid (low-activity) bat being disturbed and entering your home through a wall void or something similar.

Call Northern Pest today if you think you might have a colony in your attic; there’s still time this year to get your valves installed and minimize the risk of a bat in your home!