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.
Their eyes will open within 5-10 days but don't open fully for another 2-3 days. All kittens eyes are blue and will remain so until 12 weeks old (very much like babies) when they will develop their true colour, although some breeds do not change colour fully until 12 months of age.