What are some good/best ways to annotate essays?

In “the bat poet”, why does the bat go to sleep with the other bats are the end of the story? a.he is suffering from winter’s block and takes comfort in being among his own kind. b.he is frightened of attack from owl, so he cannot sleep on the porch. c.he is now comfortable with himself: a bat a poet. b.the porch is torn down,so he has no other choice but to sleep in the barn.