Is it only mammals that have emotions?

Humans can have difficulty understanding their own emotions at times. It’s much harder to study what’s going on in an animal’s brain, especially as you can’t talk to them. Scientists agree that a number of intelligent mammals have feelings, but they’re not alone. Owners and keepers of birds, fish and reptiles report their animals showing love, joy and excitement. Behaviourists have demonstrated that lizards make decisions based on pleasure and that chickens are as emotionally complex as mammals.

Scientists found evidence of emotions in sea bream in 2017. They think the trait evolved 375 million years ago