Even though we’re all used to these strange fleshy growths, not many people know what role they play. Birds don’t have sweat glands and aren’t able to sweat to cool their bodies. So when a chicken or turkey gets hot in hot weather, its blood goes through this comb and cools down there. What’s more, judging from the color of a comb, roosters and male turkeys understand if the females are ready for mating.