Q: My two sibling moggies used to get on really well, but now they can't bear to be in the same room. They're only 2 ½ years old. What's gone wrong?
A: Oh dear. Not all cats can cohabit with others when they grow up. The most likely compatible groups are members of the same family so you did the right thing getting siblings. Unfortunately some of these mature (the timing is right in this case) and, literally, find themselves unable to be in the same room just as you have described.
This is probably worth pursuing with a detailed behaviour consultation in your home, as some cats can fall out after a single 'unfortunate' incident that they need a little help to forget! Either way, I would suggest that you contact your vet to discuss a referral to a behaviour counsellor.
Q: We've got 6 cats, one of which, is a large Bengal and he is much more independent than the others. He will be openly aggressive with all our other cats and can be a bit of a cat bully. We've even seen him 'hunt' our other cats who try and run away from him. He charges around the house breaking anything in his way and insists on being the number 1 in the household. How can I calm him down?
A: Wow, this is a little like commanding the tides of the sea to go back. King Canute will tell you how impossible that is - I think the same about Bengals!! They can be extraordinarily motivated creatures: very intelligent, strong and territorial. When you get highly competitive Bengals like yours I would always recommend they be kept as single cats. I know this sounds harsh but they can make the lives of other cats in the same household a misery.
Some Bengals respond to clicker training (a form of training using positive reinforcement - usually food treats) so that you can train them to do other things on command that conflict with terrorising the other cats. It's a tough job for you and very time consuming.
You would probably be better off discussing your particular case with a cat behaviour counsellor visiting your home.