Bat Maternity Season

For the three most common types of colonizing bats in the United States, the Little Brown Bat (myotis), the Big Brown Bat, and the Mexican or Brazilian Free-Tail bat, the maternity season is from late May until Mid-August. Absolutely do not perform a bat exclusion during this time frame, or you will trap flightless baby bats inside the building, where they will crawl down the walls, possibly get inside the house, and surely perish and rot and smell. You'll have broken the law.

What is the bat maternity season? If you have been unlucky enough to find a colony of bats in your home, you have a bunch of expectant mothers in there. Believe it or not, only the females collect together to form these colonies, and they usually do so in your attic or in other areas of your home because they are looking for somewhere to rear their young.

For the first few months that the babies are born, they are unable to fly and this is why it is dangerous, stupid and against the law to kill the bats with extreme exclusion and repellant methods during this time. It is amazing how many people turn to poisons, fumigants and similar chemicals in a bid to get rid of the bats. Would you be quite as eager to use these if you knew how much trouble you could get yourself into if you got caught by the boys in blue, or how much more work you could be causing yourself?

When you are fumigating the bats during the maternity season, why you are essentially doing is gassing them or poisoning them. When the young bats in the bat roost cannot fly, they simply crawl around within your home, escaping into the tiny cracks in the walls, ceilings and floors of your home and dying slowly, letting off a rotting smell as they slowly decompose from somewhere in the depths of your home. What you are doing by killing bats in this manner is causing yourself more work. You are going to have to find these bats once they have crawled into the crevices of your home and if you do not, they will cause your entire house to smell like rotting corpses.

The maternity season will vary from place to place, of course, with the warmer states in American having slightly earlier seasons than the colder places. The little brown bat and big brown bat will generally come into maternity around June until August, whereas the Mexican free tail bat will come into season in May through until August, and Evening bat in April through until July.

Not only is it illegal to kill and move a colony bats during this time of their life, it is also very complicated. It is hard enough to get rid of adult bats, without having to contend with the babies as well. Bats are generally considered to be a protected species, mostly because of their importance within the eco-system, eating the insects and keeping their levels down. If you try and remove bats during their maternity season and you are caught, there are serious repercussions from heavy fines to jail sentences in some cases.

Sometimes you will find that the baby accidentally crawls into crevices in your home and the mother bats follow them in. This means that if you have managed to get the adults out of the home, the mothers will still find any way necessary to get back in to get to their young. This means that your work to remove them during this time will be essentially fruitless. It is best to wait and call in the professionals to do the job for you.

Let’s look at the worst case scenario – you are managing to exclude the adults from your home but the babies are still stuck within it. They are starving because their mother’s aren’t available so they are crawling around, desperately trying to find food. If you imagine that a colony in your home can contain around forty mothers, and most mother bats will have one pup at a time, which means that there could potentially be 40 babies, wandering around your home, dying in the walls and cracks that you can’t get to. It doesn’t matter which way you look at it, it is always best to wait until the maternity season has finished before you try and remove the pest problem from your home.

Go back to the main Bat Removal page for more information about bat maternity season.