They were fighting over the owner of them .Because that 's how cats show they are having fun .That 's just cats being cats .They were territorial around each other .
Why would the cats act this way ?
At one time I had two cats who would hiss and spit and tear about when the other came near . It was quite an impressive show of conflict . When I moved into a small house the situation became even more unpleasant . I was awoken in the night by furious , exploding encounters .