Birds and their dust bath

Matt: What are the birds that I see digging holes in the dirt around my house? I don't know what they’re trying to do, but whatever it is, they’re not making much progress. What’s going on? — E.F.S., Hillcrest

Interesting field notes, E. I’m picturing a gang of sparrows with trowels and a treasure map. If so. I’d recommend you lie low and see what they come up with. But if all you see are a few little brown birds in a shallow hole kicking up a lot of dirt, the answer’s simpler though potentially less profitable. They’ve adopted your yard as a communal dust-bath tub. Keeping feathers in good aerodynamic order is a complicated job. Like your car, feathers need a periodic wash, lube, and alignment. A good roll in the dirt is part of this routine for many species. Experts believe a dust bath helps get rid of parasites and contributes in some other way to feather care, though they’re not sure exactly how.