Dolphins often squeal when they get a fish treat, sounding much like happy children. The study in the Journal of Experimental Biology was led by Sam Ridgway of the National Marine Mammal Foundation in San Diego, California. Ridgway and colleagues work with bottlenose dolphins and beluga whales, training them to repeat behaviors and rewarding them with fish. Previous research using electrical stimulation and brain chemistry has shown that rats and primates have reward systems involving dopamine neurons.
Dolphins squeal with delight
