Crayfish (as bait)
Crayfish are smallmouth bass's favorite food, period - a live craw hopped on a rocky bottom is river bass fishing at its most honest. Same invasive-rules caveat as all live bait: local craws only.
Cut a smallmouth open (science has, repeatedly) and crayfish dominate the menu - so a live one, hooked through the tail and crawled over the rocks it came from, is as close as bait fishing gets to a sure thing on rivers. The modern caveat is serious though: moving crayfish between waters has spread invasive species catastrophically, and many places ban it. The craw you use must come from the water you fish - or stay home.
What it catches
Smallmouth above all, largemouth around rock, channel and flathead cats (a peeled tail is catfish candy), big trout, walleye occasionally.
Getting & keeping it
⚠️ Catch them WHERE YOU FISH (flip rocks, dip net at night - check legality of harvest too) - transporting crayfish between waters is banned in many jurisdictions for hard-learned invasive reasons (rusty crayfish etc.). Keep damp and cool in a ventilated container - not submerged in a sealed bucket (they drown in dead water).
How to rig it
Through the tail (second segment from the fan, point up) so it crawls naturally backward when pulled; light jighead or split-shot; softshell (freshly molted) ones are premium - fish inhale them.
When it shines
Summer smallmouth rivers, dawn and dusk on rocky lake points, and pre-spawn bass working craw flats; peeled tails for catfish anytime.
Field tips
Fish it ON bottom with slow drags and hops - swimming craws mid-column read wrong; pinch off big pincers of jumbo craws (fish grab the tail anyway, and a pinch-free bait can't hold rocks); softshells outfish hardshells 3:1.
Common mistakes
Importing bait craws to new water (ecological vandalism + tickets), fishing them under floats mid-depth, and hooks through the carapace that kill them in minutes.