My Siamese Simba is very loving to my husband and myself and for that matter, any other human stranger that he meets. He only acts aggressively to his sister, Faline. He'll give her an ominous eye once in a while, then will stalk her and pounce on her, not terribly hurting her but doing enough damage to pull some of her coat hair out. Do you think if I used Feliway spray or comfort zone plug in, it would calm Simba and easy his 'stalking' tendencies to his co-kitty sister? What other ideas do you think would work to ease Faline's defensivness toward Simba and Simba's aggressiveness toward Faline?