Nematodes are microscopic worms that are harmless to humans, animals, plants, and healthy earthworms. Beneficial nematodes aggressively pursue pest insects. When they sense the temperature and carbon dioxide emissions of soil-bome insects, they move toward their prey and enter the pest through its body openings. Beneficial nematodes control grubs that are known to destroy lawns. They are effective against white grubs and the larval or grub stage of Japanese Beetles, Northern Masked Chafer, European Chafer, Rose Chafer, Fly larvae, Oriental Beetles, June Beetles, Flea beetles.