Krystal D’Costa in her blog Anthropology in Practice brings up a myth from Madagascar on why bats hang upside down when they sleep.
It’s the story of how the drongo came to be the king of birds, but it also explains why bats sleep upside down:
There was a great fire in God’s kingdom, and He sent all the
birds to put it out. However, only the bat was successful—he beat the flame out with his large wings (which is also how he lost his feathers).
The drongo, who was pure white, covered himself with ashes and hurried back to God before the bat could get there. He said, “I put out the fire. Look at how black I am.” God was pleased and made him the king of birds.
The bat arrived soon after, but God did not believe that he had
put out the fire. The bat was understandably angry, and declared that he would forever turn his rear to God.
To this day, the drongo is regarded as a clever bird, and the bat remains upside down.
So now you know.