Question: Today while WASHING WINDOWS outdoors, I noticed THE strangest tunnels yet. They are on a south facing brick wall, having a diameter of almost 1/2". There are about 4 stuck side by side and about 6" long. Some are soil color and some are WHITE. They have about 20 holes in them and the openings face downward. They are well over 6 ft above ground level. They appear uninhabited.

Answer: These are the nests of Organ Pipe Mud Daubers, in the genus Trypoxylon. These are common, though harmless, wasps in Texas. The adults make the nests as a rearing site for their young, whom they thoughtfully provision with "fresh meat" in the form of paralyzed spiders. The holes are where the newly emerged adult wasps have emerged. The darker color tubes appear to be the most recent construction.

To learn more, try a google search on organ pipe mud dauber. These are good guys and will not attack you. Michael Merchant, PhD, BCE; Urban Entomologist; Texas Cooperative Extension