Whales are mammals known as cetaceans. Others in the cetacean family are dolphins and porpoises. Whales are descendants of ancient land-living animals that have since returned to the water. Most whales are quite large, especially the blue whale that is considered the largest in the world, measuring 108 feet in length and weighing about 190 tons.
There are two types of whales known as baleen whales and toothed whales. The toothed whales are carnivores and need teeth to hunt and kill their prey. The baleen whales are the majority of whales with a mouth that works as a sieve in their jaws so they can filter food from the water.
Whales make excellent parents to their offspring. In fact, they have a close relationship with each other in their particular pods. Although they can stay under water for long periods, they need to surface to take in air through their blowholes, making them unique from other sea life.