What do whales use to strain krill out of the water?

Whales, particularly baleen whales, use baleen plates to strain krill and other small organisms from the water. These plates are made of keratin and hang from their upper jaws in a series of fringed, comb-like structures. When a baleen whale takes in a mouthful of water, it then closes its mouth and pushes the water out through the baleen, trapping the krill inside for consumption. This feeding method is known as filter feeding.