What causes the seasons to change? Kids find out by modeling the earth's tilt using a globe, flashlight and graph paper in this cool science fair project idea.

What's the science behind those out-of-sight roots? Find out if you can trick roots into growing in different directions.

What's the best way to make DIY compost? Kids will learn about aerobic and anaerobic decomposition while learning to appreciate the value of composting.

In this plastic wrap science fair project, you'll learn about polymer permeability and find out which plastic wrap keeps food from dehydrating best.

What is surface tension? Kids will discover how water-skating insects use surface tension to keep from sinking by making a model water walker.

This science fair project idea experiments with spinning color wheels and optical illusions.

This science fair project focuses on a polymer called hydrogel super absorbent crystal which absorbs water, swelling to many times its original size.

How does the size of a vibrating surface affect the pitch of a drum? Learn about drum size and pitch with this easy science fair project idea.

What are buttress roots? In this fun science project, make a model of a rainforest tree and learn how they help trees survive in the tropical rainforest!

In this enlightening transpiration experiment, kids will explore how the loss of water from plants through transpiration contributes to the water cycle.

In this simple circular motion experiment, you'll observe tangential velocity and learn about how acceleration and centripetal force affect an object.

It's not actually that hard to get energy from garbage! Kids learn how to make biogas in the form of methane with this cool and easy science fair project idea.

Learn about the fruit fly life cycle in this experiment. Capture fruit flies to examine various stages of insect metamorphosis.

In this fun science project, learn about what happens to cut fruit and experiment with how to stop apples from turning brown.

Did you even wonder why some rocks are round and smooth while others are broken up into small pieces?

This science fair project idea develops an understanding through experimentation of which shapes are the most structurally strong.

For this science fair project, kids will learn how to make a lemon battery. They can conduct this classic experiment using readily available materials.

How do icicles form and what do they look like? Do this free science fair project and watch the formation of icicles occur right before your eyes.

Wiggly worms are known for staying buried in the soil, but how does that affect plants? Are earthworms and plant growth related?

Want to see a great example of Newton's first law? Kids will learn about basic physics with this fun, ballistic experiment.

What do worms eat? Kids find out what kinds of rotting leaves and vegetables worms prefer in this cool compost science fair project.

Camouflage is one of the most important animal adaptations in the African savanna biome. Kids create their own camouflage with this fun science fair project.

This science fair project idea highlights decomposition rates by comparing how long it takes an item to decompose in a compost pile vs. a landfill.

Check out this fun and easy 4th grade science fair project idea that tests how gravity induces positive and negative geotropism (gravitropism) in bean plants.

In this project, build an insect model that shows how the head, thorax, and abdomen fit together! Learn insect anatomy by constructing a paper mache critter.

Test out the pH levels of soil in your backyard versus soil in more wild environments to solve this science case.

Science fair project that teaches you about chemical indicators and how to make your own in order to identify various mystery solutions.

This science fair project idea investigates whether plants can survive being frozen.

The objective of this science fair project is to explore the relationship between acidic and basic compounds.

This science experiment tests why guacamole goes brown and if leaving the pit in will stop guacamole from turning brown.