Many nocturnal animals, though not nocturnal birds, have a good sense of smell and often communicate with scent marking. That sense of smell comes from the Jacobson’s organ located in the roofs ...

Animals like rabbits, house cats and deer are neither nocturnal nor diurnal. Instead, they're crepuscular. Jaymi Heimbuch is a writer and photographer specializing in wildlife conservation ...

Some animals have adapted to life after dark, thriving when the rest of the world is asleep. Here are 13 creatures that spend most of their lives in the night, revealing the wonders of the ...

Humans, who function mainly in the daylight, are diurnal. Other diurnal animals include lions, killer whales and polar bears, according to Animalia. Because cats don’t seem to fit the diurnal mold.

Instead of sleeping at night, some animals are switching to a nocturnal lifestyle. Neil Carter is a co-author on the study, which was led by researchers at the University of California at Berkeley.