My wife was out taking our dog for a walk. She came home and had a young bunny (kit) that she had found all by herself and thought the mother had abandoned it.
I told her to take it back to exactly where she found it and put it back.

Mother rabbits leave their young alone for most of the day as they go out foraging for food. They only come back to feed their kits and nest with them through the night.
They do this everyday as the kits grow and the main reason is so she does not lead predators back to her nests.
If you see a kit just leave it alone and let it be. Mum will come back and check on it during the day to make sure it is okay.