House Flies

House Flies in my grow room. Started as one.... is now 5. Do they pose a threat other than being really annoying?

not sure if they pose any threat, but they are damn annoying.
hang some duct tape...homemade flypaper

are they houseflies or gnats? I know I had a problem with fungus gnats but took care of that problem by putting some yellow sticky tape above my plants (to kill the adults) and put a small bowl of water mixed with a little wine in it (insta kill cause they smell it and go for it) along with putting a small cut of potato about 1" thick in the soil (they lay the eggs in that). But if its just flies they're just annoying as long as you dont have a huge infestation of them