The Delaware Department of Natural Resources and Environmental Control’s Division of Fish & Wildlife announced a reminder to the public that Delaware’s bat population is on the move as the bats’ pupping season approaches — and that some bats might move into places where they may not be welcomed.

The state is home to nine species of bats, which have begun their annual move from winter hibernation sites to their summer maternity colonies. The female bats return to their colonies pregnant and congregate to give birth and raise their pups. In Delaware, these colonies can often take up residence in barns, garages, attics and homes.

The Division of Fish & Wildlife notes that while bats play an important role in the ecosystem, sometimes they can be unwanted visitors to residents’ homes and outbuildings. If a resident has or has had bats roosting in an undesirable location, a bat exclusion from the building where the bats have taken up residence may be warranted.

Bat exclusions should be completed before May 15, when female bats start giving birth, to prevent trapping flightless young bats inside the building and permanently separating maternal bats from their pups, which cannot survive on their own.

For a list of permitted Wildlife Control Operators who can conduct bat exclusions, visit To review the “Best Management Practices” for excluding bats, visit