Mud daubers?

[DTisme]

There are these mud nests under our house on the wood beams - they are made of mud and have numerous 1/4"(?) holes in them. A neighbor thought they might be mud daubers, so I looked that up, but all the nests I could find only had one big hole in them. I'd say these are the size of, say, a half a potato each. Any insight and/or suggestions?

[Carey]

Have you checked the images of termite mud shelters?

ETA: both the black mud dauber wasp & the subterranean termite can build mud burrows & shelters. the shelters are more potato looking. Definitely find out what is building these, as the damage that termites can do is impressive

Look at the mud dauber shelter images on this link & you will see 2 that do look more potato like:
http://images.google.com/images?client=safari&rls=en&q=mud+dauber+wasp&oe=UTF-8&um=1&ie=UTF-8&ei=YZ7LSsXSHY_EsQOltrGLAQ&sa=X&oi=image_result_group&ct=title&resnum=4

[dfryman]

I am not sure of the name, but I had those for years under my house and they are occupied by a black wasp looking bug. I have never been stung or bitten by them. they just hover around and look at you. they are no threat. I even fished one out of my washing machine once and held it in my hand.

Donna