Some questions I have always had...and I'm not trying to be funny.
1. How often do people lose fingers from hand fishing? I've caught way to many snapping turtles in the 30lb+ range for me to feel comfortable sticking my hand in a hole.
2. How often to people get bit by venomous snakes?
3. Do you ever get used to sticking your hand in a hole, or are you nervous every time? Maybe that's what y'all are after? I don't even like reaching into muddy water to unsnag a line.
1. Not very often I would imagine, I would be more afraid of beavers than anything and most people don't noodle beaver dams unless they know it is an old one.
2. Most of the snakes we have in Central Texas are banded water snakes and are not venemous. Just like any kind of outdoor activity, pay attention to where you are putting your appendages, especially around logs and large rocks. When we noodle in East Texas or in rivers, I am much more cautious because of the increased potential for cottonmouths, gators, and beavers.
3. Depends on the type of hole. If its a hole in the bank and I've never noodled it before I still get a little leery. If its submerged concrete or rock there won't be anything under there but a fish. Holes in banks tend to hold air pockets and can increase the potential for running into animals that are best left alone, but I've also pulled some of my biggest fish out of holes like that. I've reached into thousands of holes and only run into 1 turtle and it wasn't a snapping turtle. Beavers on the other hand are no joke and can do some pretty serious damage really quick if you corner them. I've had them blow out of a bank hole on me before, but luckily I was able to get out of the way. Gators freak me out too, but we've pretty much dialed in which holes are used by gators from observation (plus they will have claw marks you can feel at the entrance of the hole).
The important thing to note is you don't just go blindly jabbing your hand into holes. You slowly, and I mean slowly, reach into a hole so you don't surprise or spook a fish (or any other animal). It's pretty easy to tell the difference after awhile.
Drowning is by far the biggest danger in hand fishing. Not from a fish drowning you, but from getting hung up down there either by getting your arm stuck under a rock or crevice or simply running out of breath. Lately, there have been a few drownings, mainly caused by very poor judgement IMO, like noodling just after a flash flood.
Pay attention and never noodle alone. Make sure the person with you knows the general amount of time you can hold your breath and have cues that you both understand if you get into trouble. If you aren't comfortable swimming or holding your breath, handfishing probably isn't for you.
Hope that helps answer your questions.
