A herd of whales is called a "pod." A pod can consist of three to 30 whales that have bonded together because of biological reasons or because of friendships.
Whales are large aquatic mammals that breathe through blowholes. The largest whale is the blue whale. It grows to be as long as 94 feet. The smallest whale is the dwarf sperm whale, which grows to be 8.5 feet long.
Whales belong to the order Cetacea and are divided into toothed whales and baleen whales. Baleen whales often travel alone or in small pods. Toothed whales travel in large pods, and they hunt their prey in groups. Whales give birth to live young every 1 to 3 years.