My cats weird behaviour
I have two cats that are friendly with each other. Rubio, 6-year-old and Blanca, 4-year-old. They've never been lovey cats but they sleep in the same room and even on the same sofa on different sections. Yesterday, I saw them smelling at each other and suddenly Rubio sink his teeth into Blanca's neck! There was no hissing previously. I was so surprised. Blanca returned the bite for few seconds and then let go hissing at him. Rubio just walked away like nothing happened. After a minute or two, they when back to normal.
Is this something I need to worry about? It seems so estrange! By the way, I have two feliway diffusers.
Has this happened to anyone else? Do you think this situation could escalate?
Thanks for your comments