A bird’s head should be a disaster zone. Yet a woodpecker slams its beak into bark thousands of times a day and flies off in a straight line. No confusion. No concussion.The trick is not toughness, but engineering. A reinforced skull, a relatively small brain, and a tight fit between bone and neural tissue limit intracranial motion, cutting shear forces that would rattle a human cortex. A spongy h...More