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!

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

Use the clues in this crossword puzzle to fill in the blanks with different types of snake names. Learn interesting facts about snakes as you go!

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

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

Help your child practice her spelling and vocabulary with this fun worksheet! Discuss with your child what it means to be cold-blooded.

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

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