1. Draw a line all the way around the bottle using a permanent marker, just below the tapered neck.

2. Use a sharp knife with a serrated blade to cut along the line, severing the top of the bottle. Cut on a cutting board so there's no damage t...

3. Remove the soda cap, then flip the top of the bottle upside down and slide it into the bottom of the bottle, like a funnel, to complete the fly...

4. Remove the "funnel" from the bottle so you can place the bait. Choose a bait for your trap. Flies are attracted to nearly any decaying o...

5. If you prefer a hanging trap, use a hole punch to punch two holes at the top of the bottle. Make sure they go through both layers of the trap. T...