When you dream flies means: The constant distractions and daily irritations in our walking lives are represented by the dreaming of flying flies. The symbol of a dreamer encouraging them to tidy up their mess. They love to feast on the dead and other gross objects in life. These bod omens are said to appear on dead people and indicate that something is not clean. Flies around the mouth can be a nightmare. They are a sign of communication, internal rot or negative speech. An attack by a swarm is an unconscious symbol of things you’ve neglected. The people and places around you are clues to where you should look.
(in Dream Dictionary)