Slightly similar to fruit flies, a phorid fly is rather small and can grow up to 1/4 in. or 6 mm. long; however, they have a distinct bump on their back that helps set them apart from the common fruit fly. They are commonly found anywhere with high temperature and humidity and an abundance of decaying matter for them to feed on.
Like the fruit fly, phorid flies appear near unsanitary conditions and can carry around diseases because of that. It is important to contact a professional exterminator service to help eliminate phorid flies from your establishment.