Chum do that - I noticed on the thread about the Zone that the bite would turn on and off seemingly at random. I had that happen to me last Monday on Kennedy Creek - Fish just quit on me for about an hour - even though right next to me others were catching them on corkies (well, not always in the mouth ) until a half hour before dark - then the bite turned on with a vengance and I started hooking them on every other cast with my fly. It was interesting that about the same time they quit biting corkies. Chum are wierd and will drive you nuts