The bait is made from a unique blend of fruit juices, proteins, and other nutrients which attract the fruit flies. Once they have landed on the trap, they are unable to fly away, so they stay put until they die.
The bait also contains an insect growth regulator (IGR) which prevents the larvae from developing into adults and laying eggs. This means that you can use Aunt Fannie’s FlyPunch! over and over again, without having to worry about attracting more insects!