Fish might not feel pain but crabs do, according to new research

Earlier in the week, researchers released a study that said fish couldn't feel pain. Apparently that isn't the case with crabs. Animal behaviorist Robert Elwood conducted an experiment with shore crabs, placing 90 of them in a tank and allowing them to choose between two darkened shelters. One shelter gave the crabs a mild shock and — after repeated trials — they began selecting the shock-free location. This type of "avoidance learning" makes Elwood believe that the crabs could sense the unpleasantness of the shock. "It's almost impossible to prove an animal feels pain," he said. "But there are criteria you can look at. If the data are consistent, a body of evidence can build up." [Source]

Click to see more on msnNOW.com, updated 24 hours a day.