When Can A Kitten Regulate Their Body Temperature?

A kitten can regulate their body temperature within 1 or 2 days, maybe earlier if they are sick.

Are kittens able to open and close their eyes? If so, how long does it take them to learn this? Can they blink at all yet? When can a kitten see in the dark for the first time? How do kittens look at you when you are looking back at them with bright lights on your face? What is it like for puppies/kittens when they get older and start walking around outside of cages/kennels. What happens when kitty has used up all there energy playing running climbing etc.? How long should I keep my litter box clean until after baby comes out of mommy’s womb (I am not sure what that means)