New Research Shows That Invertebrates Feel Pain

The Washington Post recently published an article questioning the popular notion that invertebrates do not feel pain. The media source cited experiments conducted by Robert Elwood and Rick Stein that tested whether prawns and crabs feel painful stimuli like animals with spines do, or simply have a natural reflex to threatening stimuli. The researchers found that when prawns’ antennae were exposed to acetic acid, they rubbed them as if nursing a wound, but when anesthesia was administered to them, they stopped exhibiting the pain-reaction behavior. Likewise, when crabs were given an electric shock, or when one of their claws were removed, they also rubbed the part of their body that was exposed to pain. The animals also showed a penchant for learning how to avoid painful environments. “These are not just reflexes,” says Elwood to The Post. “This is prolonged and complicated behavior, which clearly involves the central nervous system.”