Desert termites – yep these little gals are a bit on the weird side. They look for food 24/7/365 and they build tubes up and down. Instead of having to go back the same route, they go down possibly to save time on getting back to the ground and their source of water or moisture.
Termites are not generally a Do It Yourself pest issue, so call a Pest Management Professional for the best plan to keep them out.