Bog- did the "worms" come in a big rectangle or is there individual cubes or balls sealed in a blister pack? Ive gotten both and if it is the former (rectangle) you definatly do not want to leave it laying around! Besides yourfish would eat themselves to death (ok dont know if its true) you could also get a planarian infestation...if they are the kind in blister packs you could just drop one in and watch and see how quick its eaten...I like to hand feed my fish with these...its great! Also you can defrost them in some warm water and feed that way...