Michigan Cat Lover...Welcome to Pet Talk! First of all let me compliment you on your little ones. They are adorable! You mentioned that Bobby is one year old and I guess technically still a kitten at heart. When we got my second cat, as a tiny kitten, we kept him pretty much away from my first cat on the vet's advice until he could be tested. He was allowed to sniff cat #1 under the door just like you are doing. During that time he was a little devil. He chewed and nibbled and nibbled and chewed on our fingers. I was actually starting to wonder if I could handle him (silly me...he was a little over a pound at the time!) Shortly after being given the freedom to run all over the house and mingle with cat #1 he was absolutely fine. I am far from a cat expert (having actually started my love affair with cats only 8 years ago...those who have had cats all of their life may have much more to add) but I think maybe Bobby's age is playing a part in his nibbling and also being kept apart from the others. Hopefully he'll be just fine very soon. Let us know how you get on.