Every four years something funny happens with our calendars -- we add a day! Why do we do this? Discover the science behind leap year.

Did you know that light could bounce? Set up a light obstacle course with a few mirrors and watch light bounce around your room.

Dig in to the layers of the earth with this science coloring page!

Learn some new words and facts about precious minerals with this word-scramble and matching worksheet.

Our silkworm facts help your little one understand more about these special invertebrates. He'll read about their life stages and answer some questions.

Explore the circle of life with this informative coloring sheet! Help your student color and learn the names of each stage of a jellyfishâs life.

If you're taking a trip to the aquarium any time soon, be sure to print out this Aquarium Passport to bring along!

Discover some fun facts about the sun — and bring it to life with color — with this astronomy worksheet!

What's the difference between renewable and non-renewable energy? Help your student discover the various forms of energy we use each day.

How do these animals blend with their surroundings? Enjoy this match-up activity on animal camouflage for kids!

Does your child love butterflies? She'll learn all about them as she's asked to draw each stage of the butterfly's life.

Teach your kids all about the second planet from the Sun with this simple science sheet.

You have a lot in common with all the other humans on this planet. You all have noses and arms and fingernails, but what makes you different?

Read about Yellowstone's red foxes, some of the most cunning and smart animals around.

Help your student become aware of everyday energy use with this fill-in-the-blank worksheet.

If your kid is into dinosaurs, this dot to dot featuring mighty T. Rex is sure to please.

Wolves are an animal with a bit of rough past in Yellowstone National Park. Learn all about them!

What does a dog eat? Kids choose the pictures that show what kind of food each animal likes to eat in this first grade life science worksheet.

When we push or pull an object, we exert force on it. Get your child thinking about force by challenging him to describe how each person is exerting force.

Test your little nature-lover's knowledge about our feathery friends. Can she figure out which bird fits each description?

The rainforest is a vibrant, lush place teaming with life! Your little nature explorer can take an expedition to find the many hidden animals in this scene.

Your child will write about his or her favorite animal. Kids will research their favorite animals online or at the library, then write down three facts.

Crocodiles, snakes, and toads fill the page on this cute crossword printable. Can your child figure out each animal's name and write them in the puzzle?

Learn all about light refraction by simply placing your pencil in a glass of water. Warning: your pencil may not be quiet the same afterward.

Engage your little scientist with a fun word search, all about sinking and floating! He'll be learning a basic concept of physical science.

Without rain, we wouldn't have any puddles to splash and stomp in. Does your third grader know why and how rain falls from the clouds?

Think toads and frogs are the same? Think again! Check out this breakdown of the differences between the two, complete with a quiz to check your new knowledge.

Learners will get to know the bald eagle, the national bird of the United States and an inhabitant of Yellowstone National Park.

Learn about the great horned owl of Yellowstone National Park, a bird so big and mean that it has the nickname, "tiger owl."

This tree anatomy worksheet will give your little naturalist a better understanding of the parts that make up a tree.