We only recommend a grub control if grubs are feeding on your turfgrass roots. Raccoons and skunks feed on a variety of soil invertebrate such as earthworms not just grubs. http://extension.umd.edu/hgic/raccoons
The application of lawn insecticides to kill grubs is no longer recommended if wildlife is feeding on soil insects. Grub control products should only be applied to lawns that have experienced a grub problem and grubs are feed on on turfgrass roots.
Remove outdoor food sources and secure garbage cans. Raccoons may dig in turf for soil insects. Reseed heavily damaged areas.
Here are some reasons to apply a grub control. Make sure you have a grub problem. Reasons include past history of grubs, if you have a sprinkler system that keeps the soil moist for egg laying, and if we have weather conditions like wet summers and lush lawns while the adult beetles are active in June. The turf can be rolled back from the soil like a rug this is usually in late summer to early fall. Look for grubs in the upper soil surface, you may need to dig with a trowel. If the grub count exceeds 6-8 per square foot, you may want to consider treating for grubs.
In general, adult egg laying begins in July and root feeding begins in August. Grub controls are applied as a preventative (time frame is mid June through August). Look for a season long grub control that contains the active ingredient Chlorantraniliprole. This product is more environmentally friendly. See our publication on japanese beetles for more information http://extension.umd.edu/sites/default/files/_images/programs/hgic/Publications/HG78%20Japanese%20Be...