- What Is a Habitat?
- What Is a Kāheka?
- What Is a Loko Iʻa?
- What is a Solid?
- What is an insect?
- What Is Baby Gorilla Doing?
- What Is Climate Change?
- What Is Earth Day?
- What is hearing?
- What Is NASA?
- What is sight?
- What is smell?
- What is Snow?
- What Is Sprouting?
- What is taste?
- What Is the World Made Of?
- What is touch?
- What kinds of coverings do animals have?
- What Lives in a Shell?
- What Makes a Blizzard?
- What Makes a Magnet?
- What Makes a Monster?
- What Makes a Plant?
- WHAT Makes a Skunk Stink?
- WHAT Makes a Skunk Stink? Read-Along
- What Makes You Hiccup?
- What Makes: A Bird a Bird
- What Makes: A Fish a Fish
- What Makes: A Mammal a Mammal
- What Makes: A Reptile a Reptile
- What Makes: A Spider a Spider
- What Makes: An Amphibian an Amphibian
- What Makes: An Insect an Insect
- What Makes: An Invertebrate an Invertebrate
- What Makes: Four Book Collection 1
- What Makes: Four Book Collection 2
- What Miss Mitchell Saw
- What on Earth Can We Do?
- What the Evidence Shows
- What the Sun Can Do
- What to Look For in Autumn
- What to Look For in Spring
- What to Look For in Summer
- What to Look For in Winter
- What Will Hatch?
- What's Alive?
- What's for Lunch?
- What's in the Woods?
- What's in Your Pocket?
- What's Inside A Flower?
- What's New? The Zoo!: A Zippy History of Zoos
- What's that Rock or Mineral?
- What's the Point of Science?
- What's The Weather?
- What's the Weather? A What, Why or Where Book
- What's Under the Seas and Oceans?
- What's Up in the Amazon Rainforest
- What's Up in the Gobi Desert
- What's Where on Earth?
- What's Where on Earth? Dinosaur Atlas
- What’s in the Sky?
- When Cloud Became a Cloud
- When Darwin Sailed the Sea
- When Forests Burn
- When Green Becomes Tomatoes
- When I Grow Up
- When Sparks Fly
- When the Earth Shakes
- When the Sky Breaks
- When We Went Wild
- When You Became You
- Where Are the Constellations?
- Where Are the Galapagos Islands?
- Where Do Creatures Sleep at Night?
- WHERE Do Dinosaurs Get Their Names?
- Where do insects live?
- Where Does It Come From?
- Where Does My Poo Go?
- Where Does Rain, Sleet and Snow Come From? Weather for Kids (Preschool & Big Children Guide)
- Where Does the Water Go?
- Where Germs Lurk: Writing, Simplifying, and Evaluating Expressions
- Where Is Niagara Falls?
- Where Germs Lurk: Writing, Simplifying, and Evaluating Expressions
- Where Is Niagara Falls?
- Where Is Our Solar System?
- Where Is the Amazon?
- Where Is the Gas?
- Where Is the Great Barrier Reef?
- Where Is the Mississippi River?
- Where the Weird Things Are
- Where the Wilderness Lives
- Where Things Come From
- Where Wild Microbes Grow
- Who Gives a Poop?
- Who Has These Feet?
- Who Has This Tail?
- WHO Invented Bubble Gum?
- WHO Invented Bubble Gum? Read-Along
- Who Is Jane Goodall?: A Who Was? Board Book
- Who Is Mother Nature and Where Did She Go?
- Who Is Neil deGrasse Tyson?
- Who Lives Here? Desert Animals
- Who Lives Here? Forest Animals
- Who Needs a Desert?
- Who Needs a Forest Fire?
- Who Needs a Jungle?
- Who Needs a Prairie?
- Who Needs a Reef?
- Who Needs a Swamp?
- Who Needs an Iceberg?
- Who Says Women Can't Be Doctors?
- Who Was Ernest Shackleton?
- Whooping Cranes
- Whose Eye Am I?
- Whose Feet?
- Whose Footprint Is That?
- Whose House Is That?
- Whose Poop Is That?
- Whose Track Is That?
- Why Do Bush Babies Have Huge Eyes?
- Why Do Camels Have Long Eyelashes?
- Why Do Feet Get So Stinky?