I have found another way to help catch flies and it is using fruitfly medium that went bad and it produces very bad odor but it is just the kind of medium to attract and catch flies.This method seems to work well and instead of throwing out bad smelling fruitfly mediums just that kind of odor mimics the smell of rotting flesh and such and what you do is place it in a nice spot outside and poke a hole or 2 in the lid for the flies to fly in and out and you got another simple method to attract and capture flies and of course you can use the culture to produce fly larvae as well but its all in the way its used!