Among the most intelligent animals on Earth, three species of hyenas still roam in wilder parts of Africa and Asia. In general, hyenas are large, strong, flesh-eating animals that hunt a wide range of prey but mostly feed on carrion (the kills of other predators). They most closely resemble dogs but are in fact more closely related to cats. When full-grown, hyenas range from about 3 1/2 to 5 1/2 feet long and weigh between 75 and 175 pounds. Considered as smart as some primates, hyenas work in teams to hunt zebras and wildebeests. They communicate through a series of yells and growls, and their cries resemble human laughter.