I've enjoyed occasionally thinking about how life might evolve differently in other environments. And it just occurred to me, there's no real reason that an animal couldn't evolve telepathy, in the sense that, for humans, we know there are ways of transferring information that humans can't intercept (without technology), such as radio waves. So if an organism evolved to generate & receive electromagnetic waves that were beyond our range of sight, it would appear to be telepathic from our perspective.
But then I realized, in such an environment it might be that other species evolve to detect those signals as well, so it wouldn't necessarily seem like telepathy from their perspectives.
Vision has evolved multiple times on Earth, I think. Like all evolution, the behavior of vision on Earth is shaped by the environment. Our eyes are most sensitive to green, because our environments are extremely green. We can't usually focus on blue light, but there isn't really much blue in nature (since you can't focus on the sky anyway). I think maybe reptiles evolved better color vision as fruits and/or flowers evolved? Though I think early primates were nocturnal, and lost much of the color in their vision. Humans I think are somewhat unusual in how much color we can see, relative to other primates, or maybe even other mammals? Bugs and flowers have co-evolved to communicate patterns and colors (and it turns out electrical potentials too!) to get bugs to pollenate the flowers. (And sweeten the deal with nectar I suppose?)
So just as we could say that bees and flowers are communicating telepathically from our perspective—oh wait, I just realized telepathic would be a little bit more than just invisible to us, because it would be able to travel through walls too, and unlike sound, we wouldn't be able to hear it. But I guess you could think of spoken language as telepathic to any animal that lacks a sense of hearing.
In the past I've mused that if intelligent life exists elsewhere in the universe it probably has tic-tac-toe, or a very similar game. Mostly because it's such a simple game.
I think there should be a lot of room for science fiction to step up the alien environment speculation. Like how would animals evolve on a planet orbiting a red dwarf? Or a planet that is tidally locked with it's star, so one side of the planet is always day, one side is always night, and a middle ring is in perpetual twilight? It'd be neat to see a galaxy on the horizon. Or if the time between the species becoming technologically sophisticated were long enough and separated enough that multiple species were intelligent, instead of just one? (Not to say other species aren't intelligent, just that nothing comes close to the intelligence of humans.)