The fly mosquito theory
Mosquitos are only ever seen at night, flies are only ever seen during the day. The question is often asked “where do the flies go at night and where do the mosquitos go during the day?”. The answer is flies and mosquitos are the same thing, I postulate that flies are merely mosquito’s with their armour on. Mosquitos come from the same evolutionary path as the vampire and thus sun light is deadly to them. By night they roam the earth feeding on the blood of the living and by day they retire to there armour, protected from sun light and continue to scope out the world of the mortals looking for weaknesses in our defences and annoying us at BBQ’s.