I think my cats need a shrink

All of a sudden they have started hissing at each other. It is really scary especially at night. I do not know what has changed other that Pumpkin(younger) becoming a little sturdy guy. He and Sugar usually get along so well. Sugar is a cream puff of a cat and is usually calm and sleeping. Any suggestions??? judi

I'll bet if you just give them time they will work it out. Pumpkin has probably started playing a little rough or something. And... of course, they choose the middle of the night to romp!!! I have three. TWo of them have a love hate relationship. One day they are curled up together and the next day they are hissing and slapping.

You can get some sort of pheromone thing, I think it is called Feliway. We got it at the vet, but I think you can also get it at pet stores. It plugs into an outlet and looks just like a room deodorizer. It is supposed to have a calming effect on them. We used it when introducing a fully grown male inside/outside "hunter" into our household of three inside only females. It was touch and go for awhile, but the pheromone thing seemed to help somewhat.

Are they both fixed? If not maybe hormones coming into play..