Barbara Clucas, a graduate student in animal behavior at UC Davis, watched how the squirrels do it (check out her video, above). First they chew up skins shed by rattlesnakes. Then they lick themselves to spread skin pieces and snake-flavored spit on their fur. Some squirrels even gather snake odor from dirt where snakes have rested. When the squirrels curl up for their own naps, they sleep more safely.