Do the trees heal after taking damage?

Question

The other day, while playing Factorio (0.15.38) I damaged a tree with a grenade. It was almost destroyed, had red health boxes. I went to chop down several other trees and when I got to this one, the health boxes were yellow.

Do trees regenerate after taking combat damage, like the player does?

Do biters, and/or biter nests?

Answer 1

From personal experience, things do heal after being damaged some (trees, biters, biter nests, etc). The only things that don't are structures. Those you have to repair.