I'm guessing there are moles in the yard because sometimes (daily) Diggity will start tracking something, yelping at the ground, and eventually digging a hole. She digs like a crazy dog, biting chunks out of the ground and barking into the hole. All I can guess it that she can smell a mole through the dirt? Dotty just gives moral support by barking with her occasionally. Now I have all these holes in the yard about the size of footballs. In the meantime I have installed an ultrasonic mole repeller and am hoping that ends it. Any idea if I'm correct?