Adults with sleep problems and mild cognitive impairment scored higher on cognitive tests when they reported taking at least 5,000 IU of vitamin D daily
Birds add fresh greenery to their nests, but scientists still cannot explain why it helps their young
Sooty mangabeys bend the middle of their feet nearly as much as chimpanzees bend their ankles while climbing
Europe’s hyaenodonts did not disappear when rival predators expanded—they survived for millions of years