I have a pair of sturdy 14" tweezers that are supposed to be for planting things but are being used to feed my fish. Whenever I offer my warmouth something in them, he lunges, grabs the food and up to an inch of tweezer, and yanks it away, and I can hear his teeth scraping on the tweezers. Could this end up hurting him? I like tweezer-feeding him because I can get him to chase things and he gets all excited, but I'll stop if it could injure him.