Spotted hyenas are the animals that got Sarah Benson-Amram thinking about how smart carnivores are and in what ways.

Dr. Benson-Amram, a researcher at the University of Wyoming in Laramie, did research for her dissertation on hyenas in the wild under Kay E. Holekamp of Michigan State University.

Hyenas have very complicated social structures and they require intelligence to function in their clans, or groups. But the researchers also tested the animals on a kind of intelligence very different from figuring out who ranks the highest: They put out metal boxes that the animals had to open by sliding a bolt in order to get at meat inside.

Only 15 percent of the hyenas solved the problem in the wild, but in captivity, the animals showed a success rate of 80 percent.