Composting is indeed a complete ecosystem but flies don’t need to be tolerated. The best product for dealing with them is our DE powder or to sort it inhouse Make your own fly trap. This can be as simple as setting a little jar containing a mixture of red wine vinegar and dish soap on your counter. Within a day or two, you will start to notice a collection of dead little flies floating on top. If you’d like to try other trap methods, consider making a paper funnel that will invite fruit flies down into the vinegar but make it nearly impossible to fly back out.