Flatworms are well-studied model organisms because of their ability to regenerate. If the head of a flatworm is cut off, it sprouts another head, brain and all. Flatworms can also be trained. The researchers wondered whether, if they trained a flatworm to remember features of its environment and then cut off its head, it would retain the memory when it had grown a new head and brain. Remarkably, the answer is yes.
