The microscopic structure of a cat’s tongue helps keep its fur clean

T.S. ELIOT’S MYSTERY cat, Macavity, besides being a criminal mastermind able to evade the combined ranks of British law enforcement, had a coat that was “dusty from neglect”. Criminality is one thing, but this truly strains the imagination. Real cats are champion groomers.

Of the ten hours a day that a domestic cat deigns to remain awake, it spends a quarter licking dirt, fleas, blood and loose hairs from its fur. Cats’ tongues, specialised for this task, are covered in hundreds of backward-facing keratin spines. But exactly how these cone-shaped protuberances, called filiform papillae, work to give the animals such mastery over their cleanliness has remained unknown until now.