Scathophagidae  

It can be quite tricky to decide when you are dealing with a Scathophagid since, in most keys, this family drops out at the end of the key to Calyptrate families if it is not a Muscid, Fanniid or Anthomyiid. They tend to be distinguished by the lack of features that characterise these families, rather than by anything very definite that is unique to the Scathophagidae. In general appearance they can easily be confused with Anthomyiidae and some species (e.g. Leptopa, Delina, Gimnomera) could be mistaken for an acalyptrate on first glance. However, in all British species with the exception of, Leptopa filiformis, the back of the head is noticeably rounded with a patch of fine hair on the bottom part of the occiput, and this does give them quite a distinctive appearance.