I have always thought it was the male cat in the local area looking for a female , but now Im sure it is when a she (queen) cat comes into season and she call for a mate which could be all the males in the area as they mate with many males but I could be wrong GypsyX
I was wakened this morning very early by two cats beating the crap out of each other.
Unfortunately they were under my bed and the slipper that I threw didn't get far enough under. They are back to ignoring each other now. That's siblings for you!