They could make a girl snap.
Landing in her food, flying up her nose, making her swat at the air and look like a fool.
This is what my drinks look like all summer:
Yup, that's sand. The flies are actually called Fungus Flies and they breed in the fungus that is in the wet dirt of your house plants (side note: Yuck! I have decided to stop gardening without gloves). Get some sandbox sand from the hardware store and put 1/4 to 1/2 inches on top of the soil.
The water drains through the sand quickly and tricks the little buggers.
Let me know if it works for you.