There is another post that covers this very topic, and of cousrs I can't find it!!! I would keep the kittens in a place where the dogs don't have access for a little while. The dogs will know they're there though!! Do Rosco and Bo know the "leave it" command? You could use that in regards to the cats. Really, they will work it out amongst themselves. Just make sure the cats have a safe place where the dogs can't get to them. My only concern is the cats being so young and Rosco possibly thinking they are a snack. I've heard of people even putting the cats in a crate in the living room for maybe an hour or two so that the dogs can see/smell them but not harm them. Good luck!