Hi, I'm Gary Wilson, at America's Teaching Zoo at Moorpark College. Cheetahs communicate mainly vocally by a variety of sounds. Of course, if a cheetah's trying to protect its food it will hiss. They don't roar like lions and tigers, the structure of their throat is different so they can't actually make that roaring sound. They're more like a house cat in that sense, so they make a hissing sound if they're trying to protect something. If a mother cheetah has gone off to hunt, and now she's coming back to her cubs to find her cubs, her cubs will be lying in the grass hiding, and they'll make a chirping sound so that the mother can find them. And then cheetahs are one of the few cats that can purr like a house cat. So, if the cheetah is content, has been well fed, and is relaxed, just as it breathes it will purr.