Please download  the latest version of the free Flash plug-in.
Strange courting rituals run rampant throughout the animal kingdom, but female signal crayfish (Pacifastacus leniusculus) may take rank for their cruel mind games. Videos of the fish reveal that females release pheromones in their urine to attract suitors but that when a male arrives, she fights him. The authors, reporting today in BMC Biology , suggest the females may use these unconventional tactics to access the strongest and most fit mates. Those males who are rough and tumble enough to overcome the feisty females win access to her eggs.