The liquid is absorbed by the soil, where the roots take it up which in turn distributes it throughout the plant. It stays active for 12 months, protecting new and old growth. The product is basically a lot of beneficial nematodes that control Japanese beetle and masked chafer beetle grubs. Generally, grubs aren't a good thing to have in the lawn because they eat the roots of grass plants. A lot of grubs feeding in the same area will kill the grass.
Nematodes are microscopic worms that exist in most soils.
As grub and nematodes make their way through the soil, the nematode works into the grub's body where it releases a bacteria that kills the grub within 48 hours. The nematodes stay behind and feed on the grub's body, reproducing to create another generation of 35,000 or more juvenile nematodes in each grub. The nematodes mature, then fan out to find more grubs.