They are mammals. They have lungs just like any other mammal, and they have to come to the surface of the ocean to breathe. There are two main types of whales - baleen whales and toothed whales. Most baleen whales migrate. In the summer, they travel to the Arctic or Antarctic regions and feed on abundant supplies of plankton.
Plankton is clumps of small plant and animal life that drifts on the surface of the ocean.
In the winter, the whales migrate thousands of miles to the warmer tropical oceans near the equator. Most toothed whales do not migrate. Killer whales are the top predators in the ocean. Whales are from a group of mammals called cetaceans. All whales belong wo two main cetacean groups.