Fly Trapping Trials Experiment - For Teachers

In this lesson, students will run an experiment over days or weeks to test different types of traps to see which catches the most fungus gnats (also known as fungus flies). The objective is to help students understand the scientific method - how to set up an experiment, create and test a hypothesis, record information, and to think critically about their findings and how they could improve the experiment in future.

Time Required

• Setup: 30–45 minutes.
• Daily Activity: 5–10 minutes per day to run the experiment and record data in your notebook or the experiment worksheets.
• Conclusion: 30–45 minutes to evaluate the results, record findings, present results to the class, and discuss differences between student groups.

Classroom set-up

The experiment works well if the classroom is set up with stations of indoor plants and traps, assigning each station to a small group of students. This makes the experiment more hands-on and interactive. At the end, students can compare their findings with other groups.

Before you begin

Make sure to have houseplants in your classroom or home a few weeks before you start the experiment to make sure fungus gnats are present for the experiment. Water your plants often to keep the top layer of soil damp to create a good environment for fungus flies.

Look up fungus gnats on the internet to see what you can learn about them. Fungus flies are about 1/8" long, have black bodies and black eyes, and belong to the genus Bradysia. They reproduce in the moist topsoil of houseplants, and have a three-to-four-week life cycle from egg to larvae to pupa to adult. Their larvae feed on the fungi, algae, and decomposing plant matter in the top layer of the soil.

A good place for students to record their observations is in their science notebooks. This will help students keep their thoughts and ideas in one spot. Below is an example of what an observation chart might look like. If your class does not have science notebooks, you can print out the experiment worksheets for students to use to record their data and notes.

Tips

Create a routine to check the traps every day around the same time. Encourage students to draw their observations and take their own notes. For example, students could sketch the experimental setup, fungus gnats, and how the traps work.

Extensions

Test different types of traps, either by testing different liquid solutions or using sticky card traps instead. Have students prepare a poster summarizing the experiment (the problem, their hypotheses and predictions, the experiment, and their findings) to present.

If you want to emphasize communication and reporting, students can also choose additional formats to explain their results to different audiences. Remind them to think about their role, their audience, and the best way to share the message for that format. Some options might be: a newspaper or magazine article, illustrated infographic, scientific article, blog post, or social media post.

Objectives

Learn how to set up and run an experiment, to create and test hypotheses, to critically analyze and evaluate data to draw conclusions from the results, to take notes and record findings, and to write a basic scientific report with hypotheses, predictions, experimental setup, results, and evaluation.

Sticky trap image by Sabine Deviche.