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Lose the noodle rods and spring bobbers. Sometimes you have to go aggressive jigging. Get them to react instinctively on a bite. That same aggressive jigging can also translate into aggressive hook setting anticipating those light nibbles. Call it foul mouth hooking, but I learn that technique from Dave Genz.
When in doubt....set the hook! I've had them just move the line or bend the rod tip maybe a 1/16th of an inch. Rip their lips on anything that doesn't seem normal.
Sometimes give'm more bait to bite on. Hence the bite more than you can chew analogy comes into play. It's more like bite more than you can spit out immediately. It's funny in a way and will probably get you more nibbles than before. However the one that nibbles and nibbles and nibbles usally means it's stuck in the mouth.