Scientists have discovered that male fish take bigger risks when they are breeding. Research carried out at the University of St Andrews found that when male sticklebacks are in a reproductive state, they turn into antisocial feeders, leaving the rest of their shoal behind to search for food alone. But this risk pays off, as it allows them to forage for food more efficiently. The behaviour is in contrast to egg-carrying female sticklebacks, which stick with their shoals for safety and to conserve energy. Kevin Laland, professor in St Andrews' School of Biology, said: "The hormonal changes that cause a male to enter his reproductive phase may be responsible for this transition to more antisocial behaviour."