What Your Preschooler Will Learn About Worms:

- How to find worms

- Worms live in dirt and tunnel

- Worms eat garbage/compost

- Recycling

- Worms mix up soil

- Putting worms in soil will make it better for plants

- Worms like the dark

What You'll Need to Build Your Worm Farm:

- A glass or a plastic container big enough to fit dirt and worms. An old aquarium is ideal. However, you can use a plastic soda liter bottle if you don't want your farm to last for a long time

- Worms from your garden in a short-term container. A preschooler's sand bucket or Tupperware container from your kitchen is fine. Or worms from a bait store; they're usually called night crawlers

- Gardening soil (not potting)

- Sand

- A small squirt bottle

- Food (compost such as egg shells, apple pieces, tea bags, coffee grinds, lettuce, citrus peels etc. Note: Do not use dairy, meat or smelly foods)

- A cover for the container to keep it dark or a dark place to store it

How to Build Your Worm Farm:

Step 1: Have your preschooler collect worms so you can start building your worm farm; building one after a rainstorm is a great time, as is the early morning or late evening. You can also dig for them in your garden. If you truly can't find any worms, mix up an extremely mild soap water using dish soap. Lightly spray your lawn and wait an hour. Then collect the worms that will come to the surface. If you don't want to hunt for worms, go to your local bait store and ask for night crawlers.

Step 2: Layer sand and soil in your worm farm. Make sure the top layer is soil. If your soil is especially dry, use a squirt bottle to add some water to it so it stays moist.

Step 3: Add your food/compost to the top of the container. You don't need a lot.

Step 4: Add your worms to the container. Your worms will immediately start tunneling to get out of the light. They will not go for the food immediately.

Step 5: Cover the worm farm so the worms are in darkness. Note: You do not need to cover the top of the container unless you are afraid of your worms escaping. If you do place a cover on top of the container, make sure it has holes in it so your worms can get some oxygen.

Step 6: Check on your worms within a few hours. Point out to your preschooler the tunnels the worms are already making.

Step 7: Keep checking on your worms. Over the course of a few days, they'll eat all the food and mix up the soil and sand.

Step 8: Release the worms into your garden, use the soil for your plants and start all over again with a new worm farm. Or add more compost to the worm farm and see if more worms appear.

What to be Teaching your Preschooler about your Worm Farm:

- A worm's job is to mix up soil in a garden and eat garbage.

- The importance of reusing or recycling - just because something is garbage to you, doesn't mean that it's garbage to someone else or an animal.

- The soil in your worm farm is now perfect for plants because of the worms' hard work.

Suggestions for Your Worm Farm:

- Use the spritz bottle to keep the soil moist. A few squirts a day should do it. Make certain your preschooler does not over-water the worms since this will kill them.

- Keep your worms in the dark as much as possible; worms do not like light.

- Get more out of this science project by allowing your preschooler to play with the worms. Have your preschooler discover which worm is the biggest and which is the smallest.

- Point out that when your preschooler tries to pick up a worm, it wiggles. Explain that this is to keep it from being eaten by a bird.

Variations of Building A Worm Farm:

If your preschooler is very young, they may not understand layering the sand and soil so the worms can mix up the soil. Feel free to skip this step and use only soil in your container.

Hi! I'm Theresa Halvorsen, the preschool science and nature writer for Preschoolrock.com. I have twin boys and am blown away by their fascination with preschool science and how the world works around them. I am always looking for fun and simple science activities so preschoolers can learn about science and the natural world. Please contact me with any suggestions, ideas or questions you have about this site.

Helpful Tips for Parents

• Integrate science into daily routines: cooking (chemistry), gardening (biology), building (physics), weather watching (meteorology). A science-rich home requires no special equipment.

• The best science projects are the ones children generate themselves by noticing something in the world and asking why. Adult-imposed experiments are valuable; child-generated experiments are extraordinary.

Frequently Asked Questions

Are commercial science kits appropriate for preschoolers?

Commercial science kits designed for ages 4+ can be engaging starting points. Look for kits that use simple, safe materials and produce visually dramatic results (crystal growing kits, volcano kits, solar system model kits). Avoid kits with very small parts, complex safety requirements, or expected outcomes that are frustrating when not achieved. The best kits are those that leave children wanting to experiment further beyond the kit's instructions — look for kits with extension activities built in.

Related reading: See also our bubble experiments and our science experiments at home for more ideas on this topic.

🎓 Skills Your Child Will Develop

• 🏗️ Engineering Thinking — Testing structures, materials, and designs to see what works develops engineering intuition — the practical understanding of forces, materials, and design that underlies all physical construction and problem solving.
• 😌 Patience & Delayed Gratification — Experiments with delayed results — growing plants, watching crystals form, tracking weather — teach children to wait for outcomes rather than needing immediate feedback, a skill that predicts academic and life success.
• 🔄 Flexible Thinking — When an experiment produces an unexpected result, children practice adapting their thinking — a form of cognitive flexibility that makes them more resilient learners across all subjects.
• 🤔 Critical Thinking — Making a prediction, testing it, and explaining the result develops logical reasoning — the ability to move from observation to explanation that underlies all scientific, mathematical, and analytical disciplines.

Here's a fun preschool insect activity - building a worm farm! Most preschoolers are fascinated with worms. Not only are worms plentiful in gardens, but they are easy to catch and completely harmless. If you and preschooler want to learn more about worms, building a worm farm is a great preschool insect activity to do together. If your preschooler is really into worms, combine this preschool science project with Preschool Worms in the Dirt from our Craft section.