There are many varieties of crawfish (or crayfish). Some live entirely in the water. That particular one is a red swamp crayfish, often called a mud bug. They dig holes in muddy areas, even roadside ditches that often stay damp. The top of the hole is above the water line, but water is just beneath the surface.
As kids we used to tie a piece of bacon on a string and lower it in a hole, wait a few seconds, then very slowly pull the crawfish out. Once they got the bacon clamped in a pincher they were reluctant to release it. And you sure didnít want to make the mistake of letting one clamp down on a finger. One time and you learned a lifetime lesson.