In winter the common wood frog can freeze into what looks and feels like a frog-shaped ice cube. How it survives may help medical research.

Spaceships that vanish at the flick of a switch may be the stuff of science fiction, but new research suggests that objects really can be made to look invisible.

New 3-D and 4-D ultrasound scans provide lifelike views of fetuses that thrill parents and give doctors new insight on development and behavior.

Sleep is as important to our health as diet and exercise, yet millions in the United States are skimping on their shut-eye, researchers say.

The first two cloned kittens have been delivered in the U.S., and dogs are next—but animal-rights activists are calling for state and federal regulations.

Meat-eating is why our teeth grow crooked, why our jaws are small, and why we're relatively good at processing cholesterol, research shows.

The recent crash of a U.S. nuclear submarine into an undersea mountain served as a reminder that we know little about the geography of the ocean floor.

Human fossils found 38 years ago are 65,000 years older than previously thought, a new study says—pushing the dawn of "modern" humans back 35,000 years.

It might be possible to transplant embryonic stem cells from pigs into humans to grow new organs, a new study shows.

Scientists have shown that, for hepatitis B vaccine, genetically modified potatoes may be an alternative to the syringe and needle.

Pluto was discovered 75 years ago this week and remains the only planet never visited by an Earth probe. Now a new NASA mission looks to change that.

As humans prepare to court their valentines, spare a thought for some bird species, where it's the males that are left holding the baby.

If you're smart, you'll never come within spitting distance of a cobra. A new study confirms they deliberately, and accurately, aim for the eyes.

Self-censorship may play a greater role in suppressing scientific research than laws or regulations, according to a new study.

Octopuses often bend their boneless arms to form "joints" like those in human arms, a new study says—information that could drive the next wave of robot arms.