A puzzle for everyone

Mystery mud mounds


(Photo credit - Vicki Ashton)

Vicki from Maryland e-mailed me the above photos along with the following question:

"My family and I were riding along the Potomac River at Dyke Marsh (http://www.nps.gov/gwmp/dyke-marsh.htm) last weekend when we ran across several dozen of the strange mud holes. Do you have any idea what type of a creature would make them? It seems like an unusual design for a a mammal or even reptile, I would expect to see points which were worn where enter and exit the cone of mud but there weren't."

I've finally figured out who the homeowner is, what do you think? If nobody comes up with a correct answer I'll post it later in the week.

Follow-up

In less than 24 hours we already have a winner. Our first commentor pegged it:

Rob,

These little mud towers are made by a species of crayfish.

Tony Lance"

Who knew? Now let's grab a pitcher of beer and boil up a bucket of "crawdaddies", New Orleans-style. ;-)