nocturnal

Nocturnality is an animal behavior characterized by activity during the night and sleeping during the day. The common adjective is “nocturnal”. Nocturnal creatures generally have highly developed senses of hearing, smell, and specially adapted eyesight. Such traits can help animals such as the Helicoverpa zea moths avoid predators. Some animals, 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 nocturnal creatures including tarsiers and some owls have large eyes in comparison to their body size in order to compensate for the lower light levels during the night. More specifically, these animals have been found to have a larger cornea relative to their eye size than diurnal creatures, in order to increase their visual sensitivity in the low light conditions. Nocturnality helps wasps such as Apoica flavissima avoid hunting in intense sunlight. Diurnal animals, including squirrels and songbirds, are active during the daytime. Crepuscular species, such as rabbits, skunks, cats, and hyenas, are often erroneously referred to as nocturnal. Cathemeral species, such as fossas and lions, are active both day and night. While most humans are diurnal, for various personal and social/cultural reasons some people are temporarily or habitually nocturnal. The most known creatures to be nocturnal include cats, rodents, and owls, which all have heightened senses (including sense of sight).