they fly away.
They either bite or fly away from the predator.
They attack prey from behind.
They send out ultra sonic sonar waves that bounce back from obstacles to guide them by using the thin skin wings spread across the limbs to act as aerofoil and rudder.
Episode 5 - The Bat Action Hitting Aid - Fastpitch Softball TV Show
How to Build a Bat House
How to Hack a Baseball Bat
Baseball Bat Guide