We have 3 cats as of now... Cassa who is 10 years old, Demon who is 3 years old, and the newbie Twiggy who is going on 2 years old. All are fixed.
Cassa is the first one we got and she was more a "people" cat. It took her 4 months to take to Demon when he was a kitten.
Demon will not stop chasing Twiggy, he swats her, chases her - for me, it looks like he bullies her. He will sometimes growl and hiss as well. We keep Demon and Twiggy separate. Cassa and Twiggy are completely fine. We have tried redirecting with toys and Feliway treats; he will eat his wet food in front of her, but once she's done - if she walks away, he HAS TO BE THERE WITH HER! When she's in the bedroom on the "rotation" he will stay at the door or be at the door if we are in the bedroom. He even has a small tantrum if we put him in the bedroom and she's in the different place of our home.
Any ideas on what to do?