I have 2 cats that I found when babies. They are brother and sister. 2years old, spayed, neutered, and declawed. They have always been best friends, playing, grooming,inseparable. Till last night, now when my female sees her brother she growls,hisses,and speed everywhere. They live inside and destroyed my house breaking everything fighting one another. They are both sweet good tempered cats and have never fought before. I don't know what to do. Why would this happen all of the sudden. My male in the past has tried to hump my female but I would clap my hands and he would stop. Since last night if my female lays eyes on her brother she goes crazy screaming and growling. My husband wants them gone and I love my babies, I just don't understand why this happened all of the sudden without any sign or warning. Please help me!!!!