The house fly food I offer is made from the finest ingredients around. The mix is made special by myself and includes, casein, powered sugar, Bee Pollen, brewers yeast and another ingredient. Bee pollen cannot be eaten by flies unless it is ground to a fine powder, and is essential in nutrients found in flower visiting insects. All you do is put a thin layer in one of the small cups that come in the Cup-o- Flies container. as the food becomes dirty (from the flies "spit") cover it with a new thin layer. Of course you can clean the cup each time if you want or just order extra available here at MantisPlace.com! The advantage to using the dry food over honey is, the flies don't get coated in it and make the hatching container a mess.