My latest Experimental Podcast: Female capuchin monkeys don’t look any different when they’re at their most fertile. So to let the males know when they’re ready to mate, they change their behavior - making faces and following the males around. But in one group of monkeys, the females have figured out another way to get attention: throwing stones at the object of their affections. It’s a brand new behavior never before reported in monkeys.

Listen here: Flirty Female Monkeys Throw Stones at Males to Get Their Attention.