In this task, you are given a paragraph, and your job is to generate comma-separated entities present in the given paragraph. Generate entities from a given passage in such a way that (i) they are present in the paragraph, (ii) they are non-duplicate, (iii) they underwent a state change during the process. Avoid creating entities that (i) aren't present in the process paragraph and (ii) aren't significant.

A bird lays an egg. The egg hatches into a baby bird. Baby bird eats. Grows into an adult bird. The bird finds a mate. The pair build a nest. The birds lay eggs.
egg ,baby bird ,adult bird ,nest ,eggs