Although largemouths, smallmouths, and spotted bass are opportunistic feeders, their preferred foods are small fish followed by crustaceans and insects.
The bass' senses are generally tuned to detect the particular physical stimuli that its common food regularly emits. For example, a bass may be visually sensitive to motion, but not equally sensitive to all motion. Specifically, its motion detectors are fashioned to be most sensitive to the swimming, darting actions of small fish, the crawling movements of crayfish, and the fluttering actions of insects.
If bass senses are tuned for specific prey like small fish, why do they attack artificial lures like hardbaits and softbaits? Simply, because to a feeding bass these lures emulate food. When a bass sees a minnow-shaped crankbait it thinks of a minnow. When it hears a jig sliding across the bottom, the bass imagines a crayfish. You get the idea.
To say that bass view lures as imitations of natural foods doesn't adequately explain their behavior. Most bass will never see an earthworm in their lives; why then do they attack plastic worms? It cannot be because the worm resembles natural food. Likewise, what do we suppose a spinnerbait imitates? Offhand, I can't think of anything found in nature that spinnerbaits resemble even remotely, and yet they can be among the most effective lures around. Why?
The answer to the riddle lies in the fact that bass' thought processes are not nearly as complex as those in humans. As simple creatures, bass don't have the mental capacity to labor over questions of what is food or non-food, natural or artificial. They may lack any mental concept of food altogether.
Natural prey species do not necessarily stimulate the bass to a maximum degree. Minnows, crayfish, and insects have more purpose in life than serving as bass fodder. Some artificial lures ? should they better fit the sensory search criteria ? may be more attractive to bass than natural foods. The trick is to discover the sensory patterns that stimulate bass best and then match those patterns precisely.
Bass strike lures for a variety of reasons, including feeding, curiosity, territorial defense, aggravation, reflex, and what might be simply termed a pugnacious personality. Lures that are great at enticing feeding strikes may be pathetically poor at evoking other types of attacks, such as reflex strikes.
Finally, no matter how good our technology gets, bass fishing will never be a sure thing. Like it or not, the final play always lies with the bass.