If you see crows on your lawn or if your lawn appears torn up in areas, you may have a lawn grub problem. Crows actually hear the grubs in the ground feeding on thatch and grass roots. The damage crows make digging up the grubs can be worse than the damage the grubs do themselves. Skunks also love eating grubs and depending on the severity of the infestation, skunks and crows can quickly destroy an entire lawn.
If you suspect you have a grub problem, take a closer look at your soil profile. If you have more than five grubs per square foot of lawn, it is considered an infestation and action should be taken.
When purchasing a chemical control, remember that products containing Merit (imidacloprid) or Mach-2 (halofenozide) are for treating the insect eggs in the spring and are useless for late summer/early fall applications. When the grubs are already present, it will be necessary to use a chemical like Dylox (trichlorfon) or Sevin (carbaryl).
Be sure to water in the product to get results.