strange behavior

I recently rescued my 8th kitten. I usually introduce them to my other cats immediately, with caution, then migrate slowly.
This morning I placed the new kitten in our "cat room" with two male cats who seem to love the new little brother. They play nicely with the baby. However, I heard the screetching of the baby kitten and I was sitting right there and noticed that one of the two cats was sitting on top of it. I quickly got him off and thought I'll watch more closely...he did it again. Was he trying to smother him?

Have you had the kitten tested for FeLuk or FIV? If not, I'd keep him separate until you're sure he won't be passing something on to your other kitties.

I'm not sure your adult cat is trying to smother the kitten but that may be the inadvertent result if you're not careful. I think the adult sitting on the kitten is an attempt to establish dominance.