The trick is to make them bite you.
Catfish holes have two or three entry and exit points, so if you're trying to extract one with your bare hand and arm, like a "noodler" does, it's really important to have a friend nearby to clog up any other escape routes.
"Then the fish is pretty much trapped," veteran Oklahoma noodler Wade Miller explains. "He can't get out if unless he gets past you."
Confronted with a fleshy, intruding fist, the catfish will attack. He - it's a "he," because it's the males in the hole guarding the eggs - chomps down on the noodler's arm and seals his own fate.
"You know it's him, he feels like sandpaper on your arm," Miller says. "Then you just grab down on the lower part of his jaw and don't let go."
Once the catfish is hooked on the noodler's arm, the whole team joins in to help bring both to the water surface. Some of the fish are so big - the largest caught at this year's Okie Noodling tournament weighed in at 70.46 pounds - and furious they can drag a grown man to the bottom of the river and drown him. That's another reason noodling tends to be a multi-person operation.
Other dangers: Because catfish do their business in murky river waters, the noodler is never quite sure where his catch is hiding out. That means snapping turtles, carp or scale fish could be waiting. Being bitten or running up against one of those feistier brands has its own dangers. Like losing a finger. Or puncture wounds. Or puncture wounds that lead to infections that lead to losing a finger.
Republican vice presidential hopeful Paul Ryan loves noodling.
"We walk around the [river] banks looking for [a] hole," Ryan told the New York Times a few months ago. "You get your hand inside the fish and they kind of, they come up on your hand. Then you just squeeze wherever you are on that fish and pull it out.
"I know it sounds crazy, but it's really exhilarating," he said.
Noodling is only legal in a dozen states. One of them is Ryan's home state of Wisconsin. Another is Texas, which shares Lake Texoma with Oklahoma, where Ryan's wife, Janna, grew up and the family visits often.
"I want to say something about you Texans," Ryan said in a June speech. "Because you understand freedom, you now legally recognize a man's right to catch a catfish with his own bare hands."
Gov. Rick Perry and the state legislature signed off on noodling effective Nov. 1, 2011.
"I'm going to go out with some of my Okie friends," he told the audience, "and I'm going to do something that I've been doing for a number of years, and that's called noodling catfish."
Prime noodling season, Wade Miller said, runs from May to the middle of August. Incidentally, deer season for Wisconsin bowhunters begins Sept. 15 and ends in early January.
For more noodling fun, watch this National Geographic video. Fair warning: An ad for "Romney 2012? often runs ahead of the featured content.