Flies are a clear example of nature’s ability to mutate with disastrous consequences.
What we today call a fly is the unfortunate result of a fairy mishap.
Once or twice upon a time, the primary purpose of fairies was to spread pollen from plant to plant. They also granted wishes and collected human teeth (occasionally violently, in order to fulfil their quotas).
At some stage late in the Pleistocene, insecticides report, a fateful mutation occurred, possibly due to night-time copulation between one fairy and a garden gnome after a midsummer party (there may have been other substances involved). The mutated result – the first flies – rapidly spread pestilence and decay and caused grave illnesses to the fairies, who began dropping like… well, in any case, a mass decline in fairy population ensued.
At this point in time, there is little to be done about them now, but it is a sad loss to the animal world to have lost the fairy, who survives only in stories told to young children.