Female capuchin monkeys try to attract male suitors by throwing stones at
them.

Capuchin monkeys are a small New World monkey species found in Central and
South America. Female capuchin monkeys will sometimes indicate that they
are ready to mate by throwing stones at males. They may also “flirt” by
pouting, whining and shaking tree branches to attract attention. This
aggressive behavior has probably evolved because capuchins, unlike most
other primates, don't have visible physical signs of fertility and estrus.