Cortisol and other hormones release a surge of energy in the form of glucose (sugar), which the body can use to fight or flee. That rush of glucose is no problem if your body's insulin response is working correctly.
Notice that the kittensâ ears are just beginning to unfold, though their eyes remain closed. Their sense of smell, hearing, and taste are slowly starting to develop. Tweed is only three days old. After almost a week, the kittens begin to wiggle around on their own a little bit and their eyes start to open.
Kittens are born with blue eyes and this is not a guide to their adult eye colour! In a few breeds, the blue colour is permanent, but in most it will be replaced by another colour starting around 6 weeks old. The blue colour depends on the intensity of blue refraction.