Bats always sleep upside down hanging from a high and secluded spot. Their biological characteristics make it necessary for them to sleep in this fashion. In fact, a bat cannot launch itself into flight from the ground like birds can. This is due to the fact that their wings are not as powerful and cannot produce the necessary lift for starting flight. In addition, a bat’s hind legs are very weak and are not developed in a way to allow the creature to run to gain momentum for flight.
Hanging upside down gives bats an ideal position to take off into flight when necessary. These winged creatures simply let go and fall through the air, gaining the momentum that is needed to take off into flight. Another advantage that bats have when hanging upside down is the ability to hide from predators. They also do not have to exert any energy to hang upside down, since they are equipped with unique talons. These talons close around a surface and lock so that the bat can relax in its upside down position without having to worry about falling off.