White grubs are immature scarab beetles. When they feed on grass roots, the grass gradually thins, yellows, and dies. This makes the grass feel soft and spongy. Scattered, irregular, brown patches of grass appear, which increase in size over time. The root injury reduces the turf's ability to take up water and nutrients and withstand drought stress. Heavily infested grass pulls up easily. In addition, white grubs attract moles, raccoons, armadillos, and birds, which can make an already damaged area look worse.