Banging you head against the wall is not to be recommended because it sort of hurts. Yet the woodpecker does it every day and seems content and happy. Woodpeckers are able to peck at a tree trunk at a high speed (6-7 meters per second), resulting in intense deceleration forces upon impact, without sustaining any brain injury. Why precisely this can be done without injury was investigated by Yubo Fan of Beihang University in Beijing and Ming Zhang of Hong Kong Polytechnic University. The results may lead to better ways to prevent head injuries in humans.