Nocturnality in Bat: Bats are active at night which is a useful adaptation for them, as flight requires a lot of energy during day. The thin, black wing membrane called patagium may cause excessive heat absorption during the day leading to dehydration.
Nocturnality in Earthworm: Earthworms have no eyes, instead, they can sense light through the light-sensitive cells called photoreceptors present in their skin. They are very sensitive to bright light and therefore stays in burrows during the day and comes out only at night.
