YUM Baits Shad Scent. Biological Enzyme Attractant Spray is made of a special blend of enzymes and attractants that can be sprayed on any lure to increase its appeal to fish. As the bait is submerged, the attractant diffuses into the water and replicates the smell of actual live prey. It also helps to mask any fish-repelling odors that might come from you or your boat. For convenience, it comes in a handy 4 oz. spray bottle.