If you're ever lost in the jungle, follow a chimpanzee. New research suggests the great apes keep a geometric mental map of their home range, moving from point to point in nearly straight lines.

"The kind of striking thing when you are with the chimpanzees in the forest is that we use a compass or GPS, but obviously these guys know where they are going," says Christophe Boesch, a primatologist at the Max Planck Institute for Evolutionary Anthropology in Leipzig.