Noodling is an odd word, and there is no consensus on where it comes from. But I have an idea. Here, in Texas at least, creeks were sometimes called Noodles. I found this out by researching the name of a road that I sometimes passed by, "Noodle Dome Road". Turns out that Noodle means creek and the dome part was from a large rock formation near the creek. Noodling was generally practiced in creeks back in the day. For instance:
In 1939 my dad was 16 years old and went noodling but caught something a lot larger and a lot more dangerous than a catfish.
Dad grew up farming, ranching, picking cotton...in other words working very hard from before sunrise until after sunset. Anyone who only worked from light to dark was considered lazy. Other than Sunday morning and school hours, it was non-stop work, hard work. My grandfather took the family on a one week vacation at the height of summer each year. He was considered unusual for doing so.
The vacations started by loading a canvas covered wagon with food and bedding, hitching up the horses, and going twenty or so miles down into the Pin-Oak Creek bottoms. They lived up on top of Pisgah Ridge in Central Texas, and the elevation drop down to the creek was a long way down. They camped next to the creek in the shade of the large trees. They swam and fished, cooked on an open fire, and the boys slept on the ground under the wagon while the girls slept in the wagon.
Fishing was the main activity, and noodling combined fishing and swimming so it was something the boys did routinely. Noodling, for those that may not know, is a technique that takes advantage of the habit that flat head catfish have of burrowing a hole into the creek bank, then staying in that hole during the day, generally facing outwards. To noodle, it is often necessary to dive below the water line while holding your breath, then feeling along the bank for a hole, then reaching in and feeling for a catfish, then grabbing that cat by the mouth and dragging it out of the hole and up to the surface.
Sometimes there was nothing in the hole, sometimes other critters took up residence in the hole, so it was a technique that was dangerous.
My dad and his brother were noodling one summer afternoon when one of them felt of something that wasn't a catfish, way up under a jumble of logs, deep down in the cool spring fed creek water. This was a particulary deep hole in the creek, and the light that did filter down to the bottom was vague and moved with the wind ripples on the surface. They couldn't see what they had grabbed but together they pulled and pulled and just before they ran out of breath it broke free and they hauled ass with it for the surface, both holding on to it. When they sucked in some air and looked they found they'd brought up a huge old logger-head turtle. Biggest one they have ever seen or heard tell of.
They compared it to a large wash tub in diameter, and said its mouth was large enough to hold a football, sideways. Fortunately, very fortunately, they had grabbed it by its tail. Had it been the other way around one of them would have pulled back a stump instead of a hand. They got it up on the bank and went and got rope and tied it up best they could, then grandpa came and took a look and said that maybe they could give it to a zoo as it had to be the biggest one ever seen. He'd been around a long time by then and would know. But that night it escaped. Dad said it was just as well because it had probably lived a couple of hundred years to get that big and wouldn't be happy in captivity.
Now days beaver have moved south, we have one in the creek next to my house. They don't build the beaver houses that they do up north though, they burrow into the creek bank below the water line, then tunnel up and build a chamber above the water line. Sticking your hand into one of those holes could get some fingers bit off quick. Or there may be a water moccasin in there, or....who knows? There are apocryphal stories of men being drowned by catfish so big they were dragged by the hand down into deep water. And these catfish can certainly get into the near two hundred pound category. So noodling isn't for the faint of heart.
I grew up hearing about that giant snapping turtle from my dad and uncle, and as a result have never been tempted to try noodling. But for the right person, it can be a hell of a thrill and result in a lot of excellent eating.