Grubs, or grub worms, are the larval stage of Beetles. The grub worms feed in the soil during the warm days of fall. As the soil temperature falls, they burrow deeper into the soil for the winter. Depending on the weather they may be higher and lower in the soil until the weather warms in the spring. At that time, they will move up near the surface and feed on grass roots again. By early summer they are pupating to emerge again as flying adults. These bugs cause severe damage to the root system of grass and some shrubbery. The damage may first appears as drought stress, and can destroy an entire lawn. White grubs have a white colored body with a reddish-brown head.