Science Models
Science Fair Projects

Using Garden Mulch to Make a Bug Zoo

Published on Sep 05, 2023


What critters live in the messy, muddy layers just above the soil? Make some mulch and go on a critter-catching expedition in your own garden.

Research Question:

What creatures take up residence in a layer of sheet mulch?

Using Garden Mulch


1. Invertebrate field guide

2. Old margarine container or other plastic container

3. Trowel

4. Hay

5. Aged manure

6. Garden gloves

7. Newspaper or cardboard

8. Notebook and pencil


Let’s make a bug z oo! In this experiment, you’ll be creating a layer of mulch to see what kind of invertebrates it attracts to your garden.

1. Choose a time of year when bugs are active, such as spring, summer, or early fall.

2. Find two small garden plots of about 2 feet by 2 feet that you can play in, located side by side. This will be the site of your gardening experiments.

3. If you don’t know much about local bugs, get a book on bugs out of the library to help you identify the bugs in your garden.

4 . First, do a search for bugs in each garden plot. If you wish, you can put them into your container for further observation. In your notebook, write down what you find and how many you have found.

5. Next, you’ll add some mulch. In the first garden plot, place a layer of newspaper or cardboard on the ground, then add hay, and finally a layer of aged manure. This is called sheet mulch. You can add more layers of hay and manure if you wish.

6. Now wait! You’ll want to wait for a few weeks so that the bugs can settle back into your garden plots.

7. Create a hypothesis, your best guess about what is going to happen. Which garden plot will have the most bugs, and what sorts will they be?

8. Go back to your garden plots. Using your garden gloves and trowel, go through the mulched plot and find bugs. How many are there? What kinds are there?

9. Do the same with the second, unmulched plot. What bugs live there?

10. Which garden plot has the most invertebrates? Why?


The mulched garden bed will have more invertebrates than the bed that was not mulched.


Invertebrates, animals without backbones, are the most common type of animal on earth. Bugs fall into this category. These little critters often live on plants and in the soil, doing an exceptional job of catching and eating other bugs and turning raw materials into soil. When you add sheet mulch to the soil, you’re activating a whole cycle of eating. Invertebrates move into the moist mulch, and they do so to break it down into the soil. They eat through the raw materials you’ve placed there, gradually turning them into soil. If you look through a compost pile, a pile of sheet mulch, or a pile of leaves on the forest floor, you’re bound to find recyclers there – invertebrates that are working on what they do best, which is turning raw materials into soil for plants.


Coppens, Kenneth. “How to Grow Bacteria in Agar Petri Dishes”