You are describing the injury that is common from the attacks of the Tropical Sod Webworm, a very small caterpillar that is the larvae of a night flying moth. Close inspections of the grass blades reveal chewed out notches in the edges and on occasion chewed grass droppings can be found. We recommend applying a proven insecticide to control them. Come by our store and we can show you effective sprays and granular products. Our spray department can control Sod Webworms for you by setting up an appointment, call us at 850-386-2114.