Anectode

Scientists have discovered that if they cover the eyes of a harbor seal and put sound insulation headphone on its ears， the keen hunter can still use beard to detect the ripples produced by its moving prey and track the fish in remote distance. The secret lies in the bent-shaped beard. In the experiment， the researchers made a beard model of the seal and dragged it in the water tank. Bent beard model with elliptic cross section rarely swan in the water， only when a simulation of fish was put into the water tank. The model then began to twitch obviously synchronized with the water vortex produced by false prey. Those beards with special shapes can effectively utilize the energy of vortex， and even the vortex made by slow-moving "fish" far away can also make them active.endprint