There was once a great battle between the birds and the beasts. The beasts won.
On their way home, a beast met a bat. "You are a bird. I'll eat you up," said the beast. "No, no," said the bat. "I am not a bird. I am a mouse. Look at my fur and my sharp teeth." The bat then ran away safely.
A few days later, a second battle took place. This time, the birds won. When a bird found the bat, it said, "You are a mouse. I must kill you." "No, no," said the bat. "I am not a mouse. I am a bird. Look at my wings."
After several battles, the birds and the beasts became friends again. However, they could no longer trust the bat. The bat had to hide in dark places during the day. This is why bats fly only at night.