They are unevenly distributed in the front and backyards. It's really strange how quickly these appeared as I've been out hand watering for a couple of weeks and was oblivious to them, if they were there, and I don't think they were.
Could be the critters have been there forever but your watering softened the drought dried ground to where it no longer supports your weight.
Or, if yours is the only "brought back to life" lawn in the neighborhood, the nibblers came to your house because your roots are tastier and more numerous.
Is the dirt humped up or just soft? Any visible holes?
My guess would be some sort of burrowing animal attracted to your yard because the ground is soft and moist. The most likely culprit would vary based upon where you live. One dry summer I even had a problem with snakes because they liked my nice, moist yard. It could possibly be caused by subsurface drainage patterns caused by overwatering IF there are no visible humps or holes.