Vector Fruit Fly Trap uses a special formula bait that makes the fruit flies go crazy. It has a sour, vinaigrette scent that lures the flies into the trap and once inside the sink and drown into the formula. It is nontoxic and can be used almost anywhere at any time. It is easier to locate the source of fruit fly infestation by seeing the count of flies caught. The trap has a 10-hole venting lid to maximize fruit fly exposure.