I have some really aggressive girls that are so bad that they go into feed mode just from hearing the tubs opening and closing in the room when I move males around. Before I put males into those tubs, I usually spray them or tap them (the girls) with a pair of tongs ... it knocks them out of feed mode and I can then safely put a male in their tub.
Scary for sure Jas! ... Glad it worked out ok.
-adam