We have an adorable new kitten. And when she was brought home she were very energetic, but after a few days all she does is sleep and sit. She uses the litter box, comes up to bed at night and is super sweet, just seems waaay to mellow for a kitten. Any ideas about why she is so sleepy and calm at this age?

Just for context:

We have her brother too and he is acting like you would expect a kitten to. Zooming all over the place and pouncing on whatever moves.

Not our first kittens either. We are cat folk. Catnip runs deep through our veins.