Most females will form lasting bonds with other females of their family, and on average 12 females and their young will form a family unit. While females generally stay with the same unit all their lives in and around tropical waters, young males will leave when they are between 4 and 21 years old and can be found in “bachelor schools”, comprised of other males that are closer to the same age and size. As males get older and larger, they begin to migrate to higher latitudes (toward the poles) and slowly bachelor schools become smaller, until the largest males end up alone. Large, sexually mature males, in their late 20s or older, will occasionally return to the tropical breeding areas to mate.
The sperm whale is the deepest diver of the great whales and can descend to depths of over 3,300 feet (1000 m) and stay submerged for up to two hours. Average dives are 20-50 minutes long to a depth of 980-1,970 feet (300-600 m). At such great depths there is little or no solar light. Sperm whales use their highly developed echolocation ability to locate food and to navigate, making nearly constant clicking sounds that pulse through the water. Sperm whales communicate using morse-code-like patterns of clicks called codas. There is also a theory that sperm whales may stun their prey with a burst of sound. The sperm whale’s head
houses a large reservoir containing spermaceti, a clear liquid oil that hardens to a wax-like consistency when cold, and has long been prized by whalers. Ambergris, a strange substance found in large lumps in the lower intestine of sperm whales, is formed around squid beaks that remain in the stomach. It is used in the making of perfume, and continues to be valuable in spite of its widespread replacement by synthetics.