This episode has a lot of cool stuff. It mostly explores how animals communicate and work cooperatively. The episode mentions how poor humans have been at detecting the nuance of other life's activities.
The episode implies how difficult it might be to detect life from an alien world if we can't even very easily determine what other life on earth is capable of doing.
Probable the coolest example shown in the episode of some behavior we have decoded is how bees communicate through figure 8 movement and wiggles, where they think other bees should go for food or shelter.
I found it very informative and entertaining. The entire 2014 and 2019 Cosmos team does an incredible job of storytelling and communicating. I've so far seen 4 of the possible worlds episodes. Of those 4, this one was my favorite. And that's not to say that I didn't like the others as well.