An excellent tip! I find that playing some tug-o-war with a f/t is a good way to peak interest in problem feeders. Get a rat nice and warm and move it around to entice a strike. Once they're latched on some gentle shakes, twists, turns of the rodent usually results in further wrap-up and a stronger grip for the "kill". The trick is to get their instincts to take over until they get more used to f/t.