I can't tell if my cats are fighting or playing...?

This is normal cat behavior. The younger one is checking to see if the older is still the alpha ("top cat"); the older one is making sure the younger one knows that the answer is still "yes, I am."

This kind of socialization is VERY important for the cats' later happiness, when they're both adults. Cats need to establish who's the alpha, then they're usually content with that relationship.

Basically, if you can't tell whether they're fighting or playing, they're playing. You'll KNOW if they ever fight. A real cat-fight is unmistakably loud, violent, and quite frightening if they're your cats.

If they start scratching or yelping, break it up. Otherwise, let them have it out. Cats are constantly fighting for the top of the hierarchy. It's really interesting, actually. Have you ever noticed that one cat will sit in the middle of the room while the other one will walk the perimeter without making eye contact with the one in the center of the room? The one in the center is at the top of the hierarchy (at least at that given moment). The one walking the perimeter only makes eye contact if they wish to challenge the other cat's place in the hierarchy. Also, they constantly mark territory. There is always one cat who will try to use the litter box first after you clean it. There is always one cat who will try to sleep with you. When they fight, they're challenging the current hierarchy. Very interesting stuff. I wouldn't worry too much about it unless it seems like they're hurting each other - it's pretty normal considering that they're just getting to know each other. Your older cat is probably trying to let the younger one know who's boss. Mine did that too, but the younger one won in the end!!! Try to distract them with lots of interactive play time (like with a fish pole play toy or a laser toy).

They are just rough housing!!!! When my 2 boys, start playing, it ends up being a play fight, and one usually walks away, then they are friends again. Some times if I hear one of them meow, I might say, "OK boys, be nice to each other"! And they usually stop then too... Treat em like the kids!

If it was an actual fight they wouldnt want to be around each other any time.

They are just playing, don't worry. My cats play alot and sometimes when my cat angel wants something or he decides to go up on top of the computer desk and other places and start knocking things off of the places. But i love my cats. So Don't worry. They are so cute. My 2 cats sleep with me. My cat angel or the other cat nick gets mad at the puppy picking on them, the cats will smack the puppy. If someone is picking on them the cat will smack the person. I just say they deserved it.

They are playing together!!! This means that your cats have made friends with each other. If there is a lot of hissing and growling and somebody gets hurt, then they are fighting. If not then you have nothing to worry about. Be happy that your cats get along with each other!!

Sounds Ok, but keep an eye on it, just to make sure one don't get too rough with the other. I have 2 cats and our boy is 6 years and our other just turned 16. Our boy gets way too rough and he is very strong and hurts her and don't realize it, I have to interfere allot with this.

Relax, they are playing. That's how they play. Strong holds, flipping around, making sounds. It's all natural and good healthy play. They like each other. If they were fighting, claws and teeth would be out, and it would sound like a masacre in your house when they did. Teeth and claws everywhere!!! lol. It's all good, so don't fret.

Unless there is a lot a baaad noise coming from those cats, and fur literally flying out... then they are just playing. :)

Two cats really fighting is a scary sight! Yours are just playing. There would be blood if they weren't.

they are playing. As long as no blood is drawn, then don't worry. It's the older cats way of letting the young one know he's in charge.

Cats vocalize when they're angry. Don't worry, even the rabbit kicking is harmless though it certainly looks bad