Nematodes actively hunt for insect larvae, entering through natural body openings. Once inside the larvae, the nematode excretes bacteria from its digestive tract before it starts to feed and multiply. Within a few days the pest will change color and die. The nematodes multiply and develop within the dieing insect, before leaving the old host to hunt for more pests. As the number of pests decrease, so will the nematode population. For this reason seasonal releases are recommended. Nematodes have a 12 month shelf life.