Scientists don't know why all bioluminescent forms of life glow. For example, several earthworm species create a luminescent secretion that doesn't have an obvious purpose. The reason for some mushrooms' glow is also unclear, although some scientists theorize that it attracts insects that spread the mushrooms' spores. A few animals light up when nearby animals start to glow, and there's not always a clear reason for this behavior. This uncertainty exists in the ocean as well as on land.Looks like a Firefly to me they flash at one another in a species-specific pattern, ofte...

Towards evening I'd say large moth or bat.

butterfly. we get those a lot on earth...