Diurnality

Diurnality is a plant or animal behavior characterized by activity during the day, with a period of sleeping, or other inactivity, at night. The common adjective used for daytime activity is "diurnal". The timing of activity by an animal depends on a variety of environmental factors such as the temperature, the ability to gather food by sight, the risk of predation, and many others. Different behaviors may occur at different times of year; diurnality is a cycle of activity with a twenty-four hour period while other cyclic activities are described as circadian rhythms. Animals active at dawn or dusk are described as crepuscular while those active at night are nocturnal. Some animals, such as those living underground, may be active at any time of day or night.

Plants that open their flowers during the day are referred to as diurnal, while those that bloom at night are nocturnal. The timing of flower opening is related to the time at which insects and other pollinators are foraging. Some trees are pollinated by bats and these open their flowers at night; the baobab does this, and their flowers open in the afternoon and live for a single night.