What animal is called a brood?

The word "brood" doesn't refer to a specific animal. It's a term used to describe the offspring of a bird or other animal (especially a fish or insect) that are hatched or born at the same time.

For example:

* "The mother bird carefully watched over her brood of chicks."

* "The fish laid a large brood of eggs."

So, while "brood" doesn't name an animal, it describes a group of young animals.