Bats are most active from April to September when they’re raising their young (called pups) and hunting food. During daylight hours, they can be found roosting in caves, trees, abandoned mines, and under bridges. A special locking tendon in their toes helps bats hang upside down.
Up all night
The best times to see bats are dusk and dawn, when insects are most active, and when darkness protects these flying mammals from enemies like hawks. If you’re waiting by a cave for bats to emerge, stay quiet and keep your flashlight off. Texas-based Bat Conservation International has details on bat-watching sites in every state. (512) 327-9721; batcon.org
From October to March, bats in the Midwest and Northeast hibernate in caves, abandoned buildings, and hollow trees. If you discover a hibernation roost, don’t shine lights or take flash photos. Awakening a bat in hibernation will deplete the stored energy it needs to survive the winter.
Even from afar, you can distinguish bats from birds by their darting, erratic flight pattern. Bats use their agile wings–lightweight membranes of skin and bone–to perform the acrobatic maneuvers necessary to catch insects in flight.
At night, bats depend on sound waves to navigate and hunt. Using a process called echolocation, they emit high-frequency chirps that bounce off objects in front of them. By measuring the strength of the return signals, bats can determine the distance, bearing, and size of a tree, rock, and even a fluttering moth.