Extra: Cleaner fish are wrasses, a group that has been called the "primates of the fish world" because of their tool use, social cognition, and mirror self-recognition.
Take a look at this amazing wrasse (Semicossyphus reticulatus).
Sometimes intelligence is visible at first glance.

What does it feel like to be a remora?

It seems that, despite the benefits they provide, whales do not like their presence and do everything they can to get rid of them. They observe them, jump several times, and check again to see if they are still there.

(blog) phys.org/news/2025-11...

7/7 Like other mammals, we are also “vocal learners,” and very good ones at it!

x.com/i/status/198...

6/7 Large brains allow them to learn many different sounds (in a general way), while parrots with small brains are better at learning a few sounds, but really well.

5/7 Interestingly, this study has revealed that parrot species with larger brains are worse at accurately imitating sounds. Species with smaller brains, such as parakeets and cockatiels, performed better.

4/7 Of course, unlike parrots, starlings are capable of producing polyphonic sounds with greater precision. This is because they can control both sides of the syrinx independently, whereas parrots cannot.

1/7 Vocal mimicry, robots, and music

The ability to mimic sounds could be extremely common among corvids. Here, it has been found in 39 species (30%), but it is predicted that it could be present in around 82% of them.

(paper) link.springer.com/article/10.1...