I have 4 cats and 1 kitten. The oldest Waldo 6 (Male) Katie 8(female)
and Blackie 3 (male) Bella (female mother of new kitten Mia)

I am having a terrible time with Waldo and Blackie (both males) waldo attacks him every chance he gets. When Blackie first came about 8 months ago came from an abused home they got along fine.
I have to keep Blackie in the barn at night Waldo and the others (even the 3 month old kitten) chases him out of the house, One of them has to go and at this point it will be Blackie,

Any body have any suggestions, Blackie really is a good cat and I don't know why they all don't like him, it got worse since the kitten was born back in June.
Or is it becayse thy are both MALES