Termite generally don’t consume live wood or cellulose, they prefer dead stuff like fallen trees and wooden structural pieces in your home. These termites in the picture are probably a Gnathamitermes species often called grass eaters. Here is Arizona they often go after dead grass, old wooden fences, dead cactus and tree bark. Here is a great publication from the University of Arizona (Baker, Marchosky).
Have you seen these? Termite tunnels or tubes.
So you’re walking around your home and you look down and see this thing made out of mud or dirt, what is it? These are subterranean mud shelter tubes or tunnels. It’s the super highway for termites, it protects them from air, sunlight and predators. Here is Arizona we have another termite (Gnathamitermes) and this subterranean termite often plasters fences, tree trucks and cactus.