Jennifer Welsh

Fetuses show preliminary facial expressions that look like cries starting around 24 to 35 weeks. These facial movements of crying are soundless and too subtle to be felt by the mother.

Zebras' black-and-white coloration is iconic, but what color are their stripes?

If the flu shot is, on average, between 40% and 60% effective at preventing the flu, why should you get it?

As men age, their testosterone levels stay high until age 70 or so, prompting their eyebrows — and ear and nose hair, too — to grow longer and longer.

Here's how some people can squirt liquids or smoke from their eyes.

Some big cats can roar loudly, but house cats can only meow and purr. Why is that?

Snakes have evolved highly adapted fangs that act as a delivery system for toxins.

Cerebral palsy is caused by brain damage that leads to muscle weakness and problems walking. But with support, people with cerebral palsy can lead relatively normal, functioning lives.

The study found the highest rates of C-sections in Florida, New Jersey and Texas, and the lowest in Utah, Wisconsin and Colorado.

Sharing your system with certain microbes may prevent autoimmune diseases.

The little fly devours the inside of the ant's head, before taking up residence.

They preferentially react to their owner's yawns, as well.

Fishy eye structures let elephantnose fish see the forest through the trees.

A one-shot solution to the world's nicotine solution could be on its way.

The debate continues: Are dinosaurs warm-blooded, cold-blooded or somewhere in between?

Though they are closely related to cows, their brains have evolved along the same lines as primates.

Good news, though: moving-in improves your sex life (temporarily).

Men's attitudes about their bodies may be making them sexist.

A vaccine against cocaine seems to stop the drug from entering the brain and making the user high, a new study suggests.

The fossilized find includes an extinct giant wombat named Kenny.

Cheetahs can "switch gears" as their speed increases — taking more strides per second at higher speeds.

Our brains weigh the risk and reward others struggle with when making a decision.