Grubs are the larvae of beetles, often the scarab beetle. They are found mostly in yards where they will infest an area and destroy the lawn. Grubs are usually white in color, c-shaped and they are quite small. Many animals feed on grubs, such as skunks and moles. Sometimes you will find evidence of this in your yard in the form of dug-up patches of grass. You can also look for crows in your yard, which feed on the grubs as well.
The adult beetle lays its eggs in the soil during the summer. The eggs hatch and become grubs in the larvae stage. The grubs begin to feed on the grass roots until the cold weather drives the grubs deeper in the soil, where they will spend the winter. Grubs will usually dig in 2 to 8 inches deeper. When spring arrives, the grubs will crawl back up through the soil and continue eating until they mature in May or June.
Grubs usually infest in small areas, and there are certain types of grasses that they will not disturb. Grub damage is usually evident from late summer to early fall. Look for brown patches of lawn that can be removed easily. Roll back the sod and examine it for grubs. Many insects and animals can do similar damage to lawns, so be sure to check for the actual grubs in the soil. Grub damage is found in sunny areas of your yard, since grubs do not like shaded areas of lawns.
Grubs are also used for the hatching of digger wasp larvae. Digger wasps will sting the grubs and lay their eggs in a cell they attach to the paralyzed grub. The larvae will use the grub as a food source as they grow.