Responses
thats an animal of course it will do that when you don't properly take care of them. get them spayed if your going to keep them together, letting them even have kids is cruel to their kits.
TMI, they were strays and I adopted the female cat with her kitten later after the kitten was born. So it wasn't my responsibility, even I found out about their relation later after the kitten was born.
People shocked regarding Luca and Iruma attempted half blood incest but I remember my female cat HAD a child with her half brother. Same father, different mothers...