Whales breathe via blowholes; baleen whales have two and toothed whales have one. These are located on the top of the head, allowing the animal to remain almost completely submerged while breathing. Breathing involves expelling stale air (which is warm and moist), as well as some mucus and excess water from the blowhole, forming an upward, steamy spout, followed by inhaling fresh air into the lungs.[11] Spout shapes differ among species and help with identification.