For their first 100 million years on planet Earth, our mammal ancestors relied on the cover of darkness to escape their dinosaur predators and competitors. Only after the meteor-induced mass ...

More of Earth's animals are becoming nocturnal to get away from human disturbance, according to a new study from UC Berkeley that was published in Science. The study is the first effort to measure the ...

Most living mammals are active at night (or nocturnal), and many other mammal species are active during twilight conditions. It has long been thought that the transition to nocturnality occurred at ...

During the time of the dinosaurs, mammalian ancestors crept around at night out of fear that they’d be gobbled up by predators during the day. It wasn’t until most dinos died out 66 million years ago ...

For their first 100 million years on planet Earth, our mammal ancestors relied on the cover of darkness to escape their dinosaur predators and competitors. Only after the meteor-induced mass ...