Materials: A 2 litter plastic soda bottle, apple cider vinegar, 1 sheet of 12x12 scrapbook paper, scissors, glue, unwanted fruit flies. Cut the top of the bottle off using the edge of the label as a guide.
Place the inverted bottle top back into the bottle so that the two cut edges are together. If the top slides down into the bottle used some tape to hold it in place, but keep in mind that to empty the dead flies you will eventually have to untape the top. It is better if you can get it to stay in place on its own.
Cut a piece of 12x12 scrap book paper to be a little taller than your bottle. The paper won't quite be long enough to wrap all the way around the bottle, so take the extra piece that gets cut off and use it to lengthen the page so it will fit. Your paper should be a little taller than the bottle so that you can fold the edge to the exact height ad have that little overlap piece shown in this picture. I wrapped my paper around the bottle and secured it with a ribbon. Then I folded the overlap over the cut edges of bottle so my finished edge is smooth, AND the paper helps close any potential gaps that could provide an escape route to a smart fruit fly.