As calls to end fluoride in water get louder, changes to the dental health of children in Calgary, Canada, and Juneau, Alaska, may provide a cautionary tale.

Easy replication in cattle mammary glands means H5N1 bird flu is under no evolutionary pressure to adapt to spread easily in humans.

Hubble is still going strong 35 years after it was launched into space. Celebrate its anniversary with some out-of-this-world images.

A weathered sign in the Minnesota River Valley proudly proclaims: “World’s Oldest Rock.” Erected in 1975, it marks a 3.8-billion-year-old gneiss — or so scientists thought.

Societal upheaval can trigger uncertainty, which makes people susceptible to cognitive traps. Experts suggest some simple tools can help.

Warming temperatures can ramp up the activity of methane-producing bacteria in wetland soils, adding to methane emissions.

Squat rhinos lived in North America about 12 million years ago, congregating in huge, water-bound herds much like modern hippos.

Autism rates are higher than ever before, probably because of more expansive and sensitive diagnoses. Those numbers highlight the need for more support for people with autism.

Rising global temperatures are driving the sharp decline in terrestrial water storage. This trend isn’t likely to change, scientists say.

The first skeletal evidence of a gladiator show or execution involving an exotic animal comes from a Roman British man with bite marks from a lion.

Dubbed the “bone collector,” this caterpillar found on a Hawaiian island disguises itself while stalking spider webs for trapped insects to eat.

When mice encounter an unfamiliar food, neurons in a brain region called the amygdala light up (blue). If the mice start feeling sick after the meal, the same neurons get reinforced to help the mouse ...