Flatworms are infamous in biology labs for their surreal ability to regenerate heads when you decapitate them. Now, researchers have discovered that an odd developmental defect can cause them to grow ...
The microscopic flatworm (Stenostomum brevipharyngium) is one of nature's weirder creatures. Chop off its head, and it'll grow one back. Cut it in half, and it'll become two separate healthy worms.