I've just been watching a program about a team searching for and recording info on tigers in the jungles of Burma and it mentions how they mostly move around at night. I am guessing it is cooler at night which is more comfortable when you has fur. Plus tigers have the advantage of night vision so night is not of a disadvantage to them.

This made me think about the Khajiit and their night vision. Also if I'm correct the Khajiit lore has a lot to do with following the moon cycle. This has got me wondering if it is deliberate where it is written into lore where lot of Khajiit lifestyle is nocturnal having them laze around in the day due to the heat like tigers?

Like Argonians can breath underwater as back in Black Marsh they spend as much time underwater as on land, do Khajiit have night vision as a reflection on lifestyle back in Elsweyr?

Khajiit have the power of Night Eye, which was the primary reason that I played Khajiit characters in Morrowind (until I learned to cheat and turn up the brightness of my television). While claiming that all Khajiit are entirely nocturnal would likely be as misleading as claiming that all house cats sleep through the day and only wake up at night, I imagine that Khajiit are not averse to staying up at night and catnapping in the midafternoon, if necessary. Night Eye, after all, was a nod to real-life feline night vision, so it would make sense that it existed for the same reason (or was at least meant to imply that the same scenario applied).