The unequal length of the upper and lower parts of their beaks (the lower being longer), serves to steer the impact force downwards, away from the brain. Also, the woodpecker’s brain is held in a skull with uneven, spongy plates that absorb shock. Third, woodpeckers have a special hyoid bone, which reaches from their beak, loops over top of the skull to completely surround their brains. This acts to keep the brain in place. It is the movement of the brain inside the skull during impact, more than the blow itself, that causes concussions. If the brain is held in place, injury risks are greatly reduced.