Certainly seperate them as soon as possible into two secure enclosures. I would get them over on to rats. You shouldn't have a problem with that as boa's don't seem to be very prey specific at all. We just got a sub-yearling boa last month and he switched from mice to rats in a nano-second (oh...it's not a mouse....oh well...it's food...SNAP!)

BCI's have an aggressive feeding response normally. There's absolutely nothing wrong or abnormal about that at all. Seperate them and feed them in their enclosures. If you move around them when they are hungry or hunting they will strike at the tank so don't do that. Some boa's if they smack their nose striking will decide to hunt another day LOL. As long as you do regular maintenance/cleaning in their enclosures and reach in to handle them they won't equate your hand with feeding as you may read here or there.

Just don't handle them with any prey smell on your hands and never EVER hand feed a boa (well any snake but especially a boa), they have very long strike ranges. My husband used a slightly too short set of tongs once to feed a f/t prey to a 6 foot boa....ended up with a lovely "road rash" type bite from the strike being a bit too long.