Recipes for homemade fly traps include a substance to attract the flies and a container to trap the flies. One recipe calls for cutting an empty 2-liter soda bottle in half. Food that has begun spoiling is placed into the bottom half of the bottle. The half with the lid is turned upside down in the other half. The two halves are then taped together.
Another recipe uses a glass jar with a solution of sugar and water in the bottom. Paper is rolled into a cone shape and inserted into the jar opening. Flies are attracted to the sugar and enter the jar through the large end of the cone. They are not able to exit the jar and drown.
In a third recipe, a drinking glass is filled with a sugar-water solution and covered with a piece of plastic wrap. A rubber band secures the plastic wrap to the glass, and holes are punched in the plastic. Flies enter the glass through the holes but cannot get out.
Flies' sense of taste for sugar is approximately 10 million times stronger than humans'. They do not have teeth and consume only liquid or granulated foods.
Many species of flies bite humans. They find subjects to bite, including humans and pets, by sensing breath exhalations, movement and the presence of dark colors. Fly bites trigger serious allergic reactions in some people.