Dolphins and whales may squeal with pleasure too
![](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2014/08/dolphin_free.jpg?fit=840%2C460&ssl=1)
Dolphins and whales squeal after a treat in about the same time it takes the brain to release the pleasure-inducing chemical dopamine, suggesting the animals' noises are shrieks of happiness or victory.
Greg Goebel/FLICKR (CC BY-SA 2.0)