The document discusses different types of whales and how they eat. It notes that some whales have teeth while others have baleen, and describes how each type feeds. Some feed on krill and plankton by opening their mouths and straining the food from the water using baleen. Others with teeth eat larger prey like squid and shrimp. The document also mentions that some whales are blue or gray on top and lighter colored below, while others are black on top and white or gray below.