When the wealthy sheik in Qatar asked me if I wanted to enter the enclosure to pet his cheetah, I said, “I didn’t come all the way to Qatar to not pet a cheetah.” So I walked in and took a knee. The cheetah approached my outstretched hand and licked it with a tongue reminiscent of my carpenter father’s coarsest sandpaper (about a P40 for you grit fans). Other than that grating introduction the animal and I got along fine.

That feline tongues are rough is no surprise to anyone who’s experienced a housecat lick. And one function of that very uneven surface is to comb the cat’s fur and keep it exceptionally clean—in part to reduce any odors that could tip off a mouse or other prey item that the cat is sneaking up behind them. A cat’s jaw and tongue, meanwhile drive felines' unusual lapping behavior, trapping water in a column to bite off. Take a close-up look at the structures that give the housecat’s tongue its unique properties. And think about what a motivated cheetah could have done to my hand.