I'll cop to not really thinking too much about hyenas. That was a mistake.
Of all the ways there are to put off cleaning my apartment, I like learning about animals the best.
The Spotted Hyena (Crocuta crocuta) is the largest member of the family Hyaenidae, and is also known as the laughing hyena due to its unique vocalizations. They are the most common large carnivore in Africa, although its origins indicate that it might have evolved in Asia and was found throughout three continents until the late Pleistocene (Asia, Africa and Europe). In traditional African folklore it is usually seen very negatively, being a symbol of gluttony, stupidity and greed - this influenced Western perception of the Spotted Hyena as well, and conservationists believe that this lingering negative perception has an impact on how much people care about its continued survival as a species, both in the wild and in captivity.
The Spotted Hyena has a powerful build, with thick muscles in its neck and forelegs. Their rump is rounded, which is a defensive adaptation - it prevents attackers who come from behind from getting a good grip. They can measure up to 65 inches (165 cm) in body length, with a short 14-inch (35 cm) tail. Females are slightly larger than males, with the hyenas in Zambia weighing the most. Some of the largest Spotted Hyenas ever measured weighed 200 pounds (90 kg), though more average-sized adults are closer to 153 pound (70 kg). Their coats vary in color from grayish-brown to yellowish-brown, sometimes being so dark as to seem almost black. The pattern of spots on the coats is unique to each individual.
Spotted Hyenas live in clans with complex social structures. Clan size can be as large as 80 individuals, but group size is dependent on habitat and main sources of prey - clans of the Serengeti are smaller, because their prey is migratory and they need to keep up. Clans of Ngorongoro Crater are larger, because their main sources of prey tend to stay in one place. Clans have a matriarchal structure, where even the lowest-ranking female will outrank the highest-ranking male. Females tend to stay with the clan of their birth, while males will break off to join new clans at about 2.5 years of age. Remarkably, the social structure is closer to that of baboons or macaques than it is to that of other large social predators. This is evidenced by their awareness of clan members of individuals, and how they use information about their own social status and the status of others to make decisions. Also, status is not determined by size or aggression, but by complex networks of allies.
Female Spotted Hyenas are the only known mammalian species to lack an external vaginal opening. Instead, the labia have fused together to form a pseudo-scrotum, and the clitoris is large, and positioned and shaped like a penis. It is capable of becoming erect. The pseudo-penis contains a urogenital canal, through which urination, copulation and giving birth are all accomplished. This genital configuration also means that rape is physically impossible. Females mate promiscuously, forming no permanent pair bonds (similar to the behavior of big cats). They tend to favor younger males, regardless of how old they themselves are, and passive males are more successful in enticing females to mate than aggressive males are. After a 110-day gestation period, the females will give birth to a litter of two cubs - only occasionally will there be three. Spotted Hyena cubs are among the largest offspring relative to the size of their mother, and cubs are aggressive toward each other. Siblicide is thought to account for 25% of all cub deaths within their first month of life.
Males take no part in the raising of offspring. Spotted Hyena clans exhibit social denning behavior, and depending on the size of the clan, will have a large central den structure or several smaller dens, which were typically dens that had been dug by warthogs and other animals. Dens are used as an anti-predator device to protect cubs while they're young. Cubs will dug much of the deeper tunnel structures, at a size which prevents even the adult hyenas of their clan from being able to reach them.
Spotted Hyenas are extremely intelligent. Studies comparing them to chimpanzees have found that Spotted Hyenas perform better at cooperative problem-solving tests, and evidence strongly suggests that primate and hyena intelligence evolved convergently. It is believed that Spotted Hyenas, while being opportunistic hunters and scavengers, will plan to hunt particular species in advance. They also engage in deceptive behaviors, such as a female sounding the general alarm call to disrupt an in-clan attack on her cubs, or a hyena sounding the alarm call to distract the others from a morsel of food they've just acquired.
You can hear some of the Spotted Hyena's unusual vocalizations in this video: