Test your knowledge of the wild world of animal mating.

From what they eat to wear they live, test your giant panda knowledge with this quiz.

Whether you watch them at your backyard bird feeder or just see them when you're hiking, how much do you really know about our feathered friends?

What do you know about your kidneys? They don't get the acclaim of the brain or the heart, but these small organs work nonstop to keep your body healthy.

Let's see how well you know your own species' family tree.

Test your knowledge about frogs and toads with this quiz.

You go to the beach to relax and soak up the sun. But how much do you really know about the waves and the sand?

How much do you know about these ancient shelled reptiles?

Want to delve inside someone's subconscious? Graphology might hold a key.

Before you scoop up your next bowl of ice cream, test your knowledge about everyone's favorite summer treat.

They help you see the world, but how much do you really know about the windows to your soul? Test your knowledge.

Can you live without your morning coffee or afternoon soda? See how savvy you are about your daily buzz.

Many breeds have stand-out physical characteristics that make it easy to identify them, but can you name the dog from its ears?

When your head hits the pillow at night, do creatures lurk? See how much your know about terrifying dreams.

There's a whole medicine chest in the garden. Do you know which plants to use for what ailments? Test your holistic herb wits here.

How much do you really know about the ground under your feet? Test your knowledge with this quiz.

These iconic pink birds are immediately recognizable, but how much do you know about them? Test your knowledge of these beautiful birds!

Life across the globe depends on bees, butterflies, birds, bats and other pollinators. Test your knowledge about these vital creatures.

From spring showers to summer thunderstorms, rain can fall any time of year. But how does it work?

Animals use their senses to detect other animals, communicate and do some wild things. Can you identify the super senses of these animals?

Bison have been named our new national mammal. Test your knowledge of this species that's so critical to North America's ecology.

These unusual creatures are stunningly beautiful and surprisingly important to life on Earth. Show us what you know!

Step aside, retrievers and beagles, and let these rare dogs trot into the spotlight. From Pulis to Leonbergers, how much do you know about these breeds?

The online dictionary Dictionary.com added a number of popular words culled from headlines and social media. Can you define them?

Sheep provide us with meat, clothing and even scientific illumination, but how much do you know about them? Find out with this quiz.

We use calendars to keep track of our days, our weeks and our years. But how much do we really know about them?

Test your knowledge of all things autumnal.

Bacteria live everywhere in your body, including your gut. These microbes have quite an impact on your health. Do you know what they do?

Whether it's a white lie or a whopper, fibs are part of our daily lives. We like to think we're honest but, well, we're not. Test your falsehood expertise.

The Earth's mountains, rivers, animals and rocks have been around for millions or billions of years. Do you know which ones have been around the longest?

Dogs have incredible senses and are like superheroes on four legs. Take this quiz to test your canine know-how.

National Park and Earth Week are right around the corner — see how much you know about our nation's protected areas.

From the cheetah to the hare, so many creatures are wickedly quick. Test your trivia smarts on what makes them so swift.

Whether you're crying tears of joy or crying over spilled milk, how much do you really know about the tears rolling down your face?

Lightning is more than just a stunning spectacle. Take our quiz to see how much you really know about this electrifying natural wonder.

Think you know everything about that special day of scary movies and sugar highs? Test your Halloween smarts ... if you dare.

You use pasta in sauce, in soups and in salads. But do you know the names of the different pasta types?

When the going gets tough, some animals get going — to bed. Take our hibernation quiz to see how much you know.

Every two years, the National Science Foundation asks 10 questions to see how much Americans know about science.

Web site and mobile app help you find the lowest gas prices in your area.

If fracking techniques pollute water supplies, what will happen to beer production?

Famed architect Renzo Piano completes a self-sustaining micro-home named Diogene.

Mayor Sadiq Kahn wants Londoners to stay hydrated with public water fountains while generating less plastic waste.

The Museum of London will showcase part of a 143-ton chunk of fat, diapers and baby wipes that was removed from the city's sewers.

Ubiquitous Mardi Gras beads can be made of other things: Biodegradable seed bombs, anyone?

There's no perfect way to dispose of your dog's waste, but here are some ideas.

As much as 66 metric tons of human excrement from visitors to Alaska's Denali National Park could soon be released into the pristine Alaskan coast.

The endangered African wild dog has a nose for democracy, according to a study, which explains how the dogs "vote."

When you can smell garbage from miles away, pizza doesn't stand a chance with bears.

Moose are increasingly unleashing their frustrations on hunters, motorists and lawn mowers.