Tiny, shapeless invaders can find their way from ponds to the human brain and cause an infection so severe that it has a 95% fatality rate. The amoeba Naegleria fowleri naturally lives in ponds, feasting on bacteria, but once it enters the human body, it makes a run for the brain tissue, traversing complex, tight spaces to reach its destination.
Harmless amoeba's tight-space crawling offers clues to how its deadly relative invades the brain
