Burrowing Crayfish: What's that mud hill near the ditch?

Burrowing Crayfish Mud Chimney

The Burrowing Crayfish creates mud columns or chimneys alongside ditches or in low-lying wet ground. The stack is formed as the crayfish pushes mud out of it's habitat tunnel. The chimneys near my home are along a ditch that ranges from a shallow mud puddle to a 2-foot deep creek. The crayfish live in underground water pools and mud. They are rarely seen because they are nocturnal. 

The Southeastern United States has over 300 crayfish species.

This 4-minute video shows a scientist catching a burrowing crayfish. At the end of the video, you get a good look at the crayfish.

Sources:

Video: https://www.youtube.com/watch?v=665N7MKI5mM&autoplay=1&app=desktop

N.C. Cooperative Extension
 http://www.ces.ncsu.edu/depts/ent/notes/Ornamentals_and_Turf/lawn/note126/note126.html

N.C. Museum of Science
http://naturalsciences.org/research-collections/research-specialties/invertebrates/john-cooper

University of Illinois Extension http://hyg.ipm.illinois.edu/article.php?id=56

UNC Charlotte Publication
http://ui.uncc.edu/story/crayfish-streams-north-carolina-fishing