The Vector 960 Fruit Fly Trap will not help find the sources of an infestation. It will attract and trap the fruit flies in the area. To find the source you will need to check drains, food items that may not be sealed, waste receptacles, etc.
The Vector 960 Fruit Fly Traps do not have actual poison in them, They have a fruity, vinegary smelling liquid in them that attracts the fruit flies. Once inside the trap, the fruit flies cannot get out.