To be seemed는 뭐야. It makes bats seem like part of their hiding place.
Take off.
Underdeveloped.
When 삭제.
Gives bats an ideal position.

Bats are very unique animals because they are the only mammals that can fly and they always hang upside down when they sleep. There are two reasons why they hang upside down. First, hanging upside down hides them from predators which are active at day by making the bats seem like part of their hiding place. Second, unlike birds, bats' wings are weak and can't give enough lift for the bats to take off from dead stop. Also, their hind legs are underdeveloped so they cannot run at enough speed to take off. However, hanging upside down always gives bats an ideal position to drop and fly.