One month ago, I moved to a new townhouse with my 7 month old kitten, Mars (neutered) My roommate already has 3 senior cats, all fixed, one male (Hunter, 11) and 2 females (Cleo 11, sister of Hunter) (Moo, 8-11). Mars was an orphaned cat, found at 4 weeks old without littermates or a mother. I have been trying to slowly introduce the 4 cats. Hunter seems the most curious about Mars while Moo and Cleo want nothing to do with him and hiss/growl if he enters within a few feet of them, or even accross the room. For the first week, they had no contact except maybe smelling each other through the door. Then I slowly started scheduled feeings to the point where the cats eat breakfast and dinner about 5 feet apart with Mars in his playpen so everyone can see each other. Mars hasnt hissed at any of them once, and chirps at the other cats when he sees them from his playpen. I think he is super excited to meet them, a little *too* excited. I let him start doing meets with the other cats and he does not at all understand that hissing means "go away" and "i dont want to play with you" and will continue to paw at the other cats as they hiss. Recently he has began to show signs of stress when left in my room while I'm out at school. He will dig at the carpet near the crack in the door until it pulls out. I tried piling t shirts near the door but he just chooses a different spot to dig up. So, yesterday, I let him out while i left the house. No one was hurt or scratched, and there was no fur anywhere (and mars is super fluffy) so I dont suspect he got into any fights. But I still am a little worried with the amount of hissing from Moo and Cleo. It might also be relevant that I'm a first time cat owner so I might just be a little unduly freaked out lol. Im wondering if I could get any input as to how to make this process easier? How long did it take your kittens to get used to being around senior cats and vice versa??