a worm is a worm..before you buy them look at them..if you see dead ones then you dont buy.. dead worms arnt good ..bait shop is probley the best way to go..although ive used walmart worms and no troubles..like all feeders if of a good quality then all is well. walmart worms are canadian so normally there good..during winter im more careful of them due to slow sales on them ..so if i see mold or dead ones i wont buy..plus ive seen mold growing on petsmart worms and i didnt buy..bait shop id prolly the best source due to a fresh worm presence..if you wanted to you can keep them in a dark colored tub and raise some in eco earth and have a contant suppy of fresh worms..ok now im HUNGRY