Nocturnality is an  behavior characterized by being active during the night and sleeping during the day.

The common adjective is ““, versus diurnal meaning the opposite.

creatures generally have highly developed senses of hearing, smell, and specially adapted eyesight.

Some , such as cats and ferrets, have eyes that can adapt to both low-level and bright day levels of illumination (see metaturnal).

Others, such as bushbabies and (some) bats, can function only at night.

Many creatures including tarsiers and some owls have large eyes in comparison with their size to compensate for the lower light levels at night.

More specifically, they have been found to have a larger cornea relative to their eye size than diurnal creatures to increase their visual sensitivity: in the low-light conditions.

Nocturnality helps , such as Apoica flavissima, avoid hunting in intense sunlight.

Diurnal , including squirrels and songbirds, are active during the daytime.

Crepuscular , such as rabbits, skunks, tigers, and hyenas, are often erroneously referred to as .

Cathemeral , such as fossas and lions, are active both in the day and at night.

Last Updated on 3 years by pinc