On #NationalPuppyDay, let's learn why, exactly, pictures of puppies melt our hearts.

Vintage photos of adorable puppies

It's official: For the first time in the United States, a bumblebee species has been declared endangered.

First U.S. Bumblebee Officially Listed as Endangered

The majestic monarch makes an epic journey— up to 3,000 miles (4,500 km)—to the Monarch Butterfly Biosphere Reserve in Mexico.

Swarms of Monarch Butterflies Go Here Every Winter

It's that vernal equinox time of year: From flowers to festivals, here are some of our favorite National Geographic photos of spring.

'Tis the Season to Be Blooming: 16 Photos Celebrating Spring

In Manila, the capital of the Philippines, a declaration of war against drugs has led to thousands dead on the street. How much is too much? #Explorer
Breathtaking views of sea coasts, a trio of traditional Irish wedding crashers, and a woman bending backward to kiss the Blarney Stone. #StPaddysDay

For St. Patrick's Day, 16 Pictures That Transport You to Ireland

Albert Einstein was a scientist, a rebel, a husband, and a target. #Genius is a new series from producers Ron Howard and Brian Grazer.
Happy Birthday to our dear Albert Einstein! #Genius
Pi day + Einstein's birthday = Apple Pieinstien Day! #genius
This is the story of how the world became modern. #Origins
Evidence of pain-killers is just one intriguing detail pulled from a closer look at the DNA in ancient tooth plaque.

Prehistoric 'Aspirin' Found in Sick Neanderthal's Teeth

Fish on! #WickedTuna is coming back next week!
Think giraffes are innocent? Think again...
His was one of the most spectacular minds of our time. #Genius
"They touched just about every mission you can think of."

The Secret History of the Women Who Got Us Beyond the Moon

One of Kenya's last great tusker elephants was reportedly shot and killed by poachers. It's estimated that as few as 25 tuskers remain in all of Africa, and only 10 were observed by the Tsavo trust in January.

One of Africa's Last Great Tusker Elephants Killed by Poachers

Coral, polar bears, and frogs are among the species hit hardest. #WorldWildlifeDay

7 Species Hit Hard by Climate Change