this scrunching behavior

Some thrifty biologists enjoy working with planaria, a genus of flatworms, because you can chop them up and each piece grows into a whole new flatworm which means you only ever have to buy one. Some experiments have involved grinding them up and feeding them to their peers to see if memories could be transferred in this way. Which – Eeeww – but also this later reassessment: “Subsequent explanations of this scrunching behavior associated with cannibalism of trained planarian worms were that the untrained flatworms were only following tracks left on the dirty glassware rather than absorbing the memory of their fodder.”