Asked by: Ella Ward, Manchester
Cats have hard, backwards-facing spines on their tongues, called filiform papillae. These work like a comb for grooming their fur, and are also used to rasp meat from animal bones. Cats are solitary hunters, but are also small enough to be prey for other animals, so grooming is important to minimise their own scent and make them harder to detect. Dogs evolved from pack-hunting wolves and grooming isn’t so important, so they have ordinary, smooth tongues.
Subscribe to BBC Focus magazine for fascinating new Q&As every month and follow @sciencefocusQA on Twitter for your daily dose of fun science facts.