Why bats hang upside down. 혹은 two reasons for hanging upside down.
Take off from the ground.
Underdeveloped.
Bats hang upside down.

The professor explains why bats hang upside down for two reasons. First they have to hide from predators. This is because bats sleep during the daytime so it is easy to be hunted by predators. Second, bats cannot take off from the ground. This is because they have small and underdeveloped legs so they hang upside down in order to fly. For these reasons bats hang upside down.