Guddlers live in difficult times, since the activity that goes by the name of guddling is illegal in many places, including the UK and most US states.
It’s a method of fishing that requires only the bare hands, hence convenient for poachers who find rods and tackle both cumbersome and too obviously revealing of their intentions. It’s also called tickling and is linked in particular with fishing for trout. In parts of North America its practitioners call it noodling, though they usually reserve that word for hunting catfish, beasts so well equipped to fight back that to do so is to engage in an extreme sport.
Trout guddling requires patience and skill:
There had been a swift and noiseless rush underneath the stone; a few grains of sand rose up where the white under part of the trout had touched it as it glided beneath. Slowly and imperceptibly Winsome’s hand worked its way beneath the stone. With the fingers of one hand she made that slight swirl of the water which is supposed by expert “guddlers” to fascinate the trout, and to render them incapable of resisting the beckoning fingers.
The Lilac Sunbonnet, by S R Crockett, 1894.
The verb guddle has been most associated with Scotland, and may be derived from Gaelic, though its antecedents are obscure.