Some fly problems can be resolved quickly. All it takes is a quick swat or two and the problem is gone. Most homes have a fly swatter for this purpose. The accidental invasion of an individual fly here or there is very common, and we all know the solution. Swat! No more fly.
Here is a quick primer on flies, courtesy of Penn State University College of Agricultural Sciences, and some tips on how to keep those flies from turning your home into a petri-dish. Warning: if you are easily grossed out, you may want to skip to the tips section of this article.