Q: How does a mud dauber make the buzzing sound when nest building? The wings do not appear to move.
A: Mud daubers do indeed make a buzzing sound when they are working. I’ve noticed it when visiting barns and sheds. I don’t hear the buzz when they fly, so my bet is that their wings are hitting/rubbing the clay walls of their “tubes”. It wouldn’t take much movement to make a sound and if the wings vibrate only slightly the hard mud surface would amplify the noise. My bet is that the noise is not defensive. It’s simply a byproduct of her happily constructing the clay cells in which she will deposit spiders and the eggs that will eventually hatch and consume the hapless creature.