In April 2005, Zazi, one of the National Zoo’s female cheetahs, gave birth to six cubs.

What Animal is the Best Mother?

Cheetahs and gorillas have some of the strongest maternal instincts, according to a National Zoo biologist

Matina Kalcounis-Rueppell deciphers the ultrasonic chatter, shown here plotted on a spectrograph, of a deer mouse.

The Mystery of the Singing Mice

A scientist has discovered that high-pitched sounds made by the small rodents could actually be melodious songs

"We're just seeing the start of matching patients with the right drug and seeing rapid improvements," says Dr. Brian Druker.

A Triumph in the War Against Cancer

Oncologist Brian Druker developed a new treatment for a deadly cancer, leading to a breakthrough that has transformed medicine

Spider monkey (Ateles geoffroyi) hangs by tail with mouth open.

Wild Things: Spider Monkeys, Fire Ants, Hagfish and More…

Dinosaur “thunder thighs” and fast-flying moths

Argentinosaurus and Futalognkosaurus, pictured, from prehistoric South America, stretched more than 100 feet long and weighed in excess of 70 tons.

How to Build a Giant Dinosaur

Sauropods were humongous creatures, but how they got so large is a mystery that paleontologists are still trying to unravel

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