I adopted two kittens from the pound two days ago. One boy - 11 weeks, and one girl - 12 weeks. They are so sweet, and we are very happy we decided to adopt two, they make a great pair. They both took right to using a litter box, and they seem to be adjusting to their new home exceptionally well. The boy kitten is much less active than the girl, don't get me wrong, he will get up and play, and run around, but, he certainly likes to nap more than the girl kitten. Is this just a difference between the sexes, or the different breeds, or even age? Or do I need to take him to the vet to make sure he isn't ill? (Not showing any signs of illness though, clear eyes, nose, ears - no coughing, or sneezing, and does have a very healthy appetite.) I'm a new kitten mom, and just don't think I can be too careful! -- Also, I've been reading mixed opinions online about litter boxes. Some say they should each have their own, and others say one for multiple cats is okay. They are sharing one now, and they don't seem to have any problem with it. Should I just let them continue to share? I just want to make sure I'm taking care of them properly. Any answers or other advice??