The crows may be doing you a favor by indicating that you have a grub (beetle larvae) infestation in your yard. Crows can actually hear the grubs chewing on the grass roots, and when they hear enough of them down there it is worth their time to dig them out of the lawn for food. Have your lawn care company take a look and recommend some treatment options. Do it yourselfers should do an internet search for methods of organic lawn grub control.