[Shorel]

Not really common to 'animals' in general, for example reptiles only have the very basic instincts of eat, reproduce, fight.

Insects don't have emotions, they barely have hyper specialized sensors as brains.

However, emotions efficiently direct behaviours in mammals. They enact immediate and persistent responses.

We can say without much doubt that emotions in mammals are similar to our own emotions.

The big unknowns are animals further away from us, which are demonstrably intelligent, like birds and octopuses.

[sitkack]

How do you know insects don’t have emotions? Bees have been shown playing. Spiders have REM sleep.

[Shorel]

Because there is not a limbic system on insect's brains. It is just too small.

What does REM sleep have to do with emotions? REM sleep is retraining of the brain over the experiences of the previous day. It is a pure intellectual activity, it doesn't need emotions.

In fact, emotions are not an emergent feature of brains just by themselves. They require parts of the brain specifically dedicated to emotions. Like a limbic system.

As I said, Octopuses can have something like a limbic system, with their big complex brains.