Did you know that invertebrates don't have backbones? Find out some different types of invertebrates with the clues in this crossword puzzle.

Use clues to fill in the boxes in this crossword puzzle, and learn more about freshwater fish along the way.

Test your knowledge of prehistoric animals with this life sciences crossword puzzle!

Do you know the functions of the primary organs in the human body? Put your knowledge to the test with this fourth- and fifth-grade crossword!

Use your knowledge of sea creatures to fill out this crossword puzzle.

Kids learn important plant and animal cell vocabulary as they plug the words into their correct spots and complete the puzzle.

What's the animal that swims upstream? Help your child figure this out with this cold-blooded animal crossword puzzle worksheet.

Dinosaurs and other creatures don't exist anymore! Learn the names of some extinct animals, and look for them in this fun wordsearch puzzle.

Review the different body parts with a fun crossword! This is a great way for your little doctor-in-training to review the basic organs and their functions.

Children learn the fascinating physics behind lightning, along with a few fun facts, in this physical science worksheet.

Which comes first, genus or phylum? To complete this life science crossword, kids need to put the 9 levels of biological classification in the correct order.