The food scraps you have placed into your hungry bin are very attractive to a host of other critters, not just worms. Normally this is not a problem, but in the warmer months, fruit flies can be an issue. This is especially true if you are eating a lot of fruit like kiwi fruit or bananas, which have high sugar levels. The best way to reduce the fruit flies present in your hungry bin is to ensure that you are adding enough fibre to balance the acidity and to cover the food with a layer of newspaper or leaves each time you feed your hungry bin. Sprinkling some dolomite lime on top of the food will also help reduce the acidity that is attracting the fruit flies.