When we walk through the lawn or disturb the veggie plants, it seems to disturb what appears to be white flies. We've started washing the veggie plants with water and spraying with white oil, but cornered about how many there are in the lawn. We're in a new house and the garden is still being established so there's not a lot of close growth. Can white flies nest in lawns and spread to veggie bins and how do you get rid of them?