Releasing a steady stream of urine to attract a mate and then fighting off anyone who still dares to approach you doesn’t seem like a great idea for getting sex. But this bizarre strategy is all part of the mating ritual of the signal crayfish. A female’s urine, strange as it sounds, is a powerful aphrodisiac to a male.

If the duo blocked the female’s nephropores (her urine-producing glands), the males never showed her any interest. If they met, they did so aggressively. But when the duo injected female urine into the water, things took a more lustful turn, and the males quickly seized the females in an amorous grip. Female urine is clearly a turn-on for males.

But the