Bats aren’t strong enough to take off from the ground like birds. By hanging upside down, they can drop right into the air and start flying. High-up tree branches and other roosting spots also give bats a place to hide from predators during a day. Unlike your hands (which require muscle power to hold a tight grip), bats’ feet close automatically on branches the instant they start hanging upside down.
By hanging out where few animals would think to look — and most can’t reach anyway — bats can enjoy a safe snooze. You might think bats would have competition from birds and other flying creatures, but the places where bats roost are not typically areas where it would be possible for birds to build a nest.
Bats have developed a special adaptation that makes sleeping upside-down as easy and effortless as sleeping in a bed is for humans. If you clench your fist around a baseball, your body uses muscles and tendons in your fingers, arms, wrists and hand. As the muscles in your arms contract, they pull on tendons, closing your fingers around the ball.
Picture Credit : Google