<P> Many plant species native to arid biomes have adapted so that their flowers only open at night when the sun's intense heat cannot wither and destroy their moist, delicate blossoms . These flowers are pollinated by bats, another creature of the night . </P> <P> In zoos, nocturnal animals are usually kept in special night - illumination enclosures to invert their normal sleep - wake cycle and to keep them active during the hours when visitors will be there to see them . </P> <P> Hedgehogs and sugar gliders are just two of the many nocturnal species kept as (exotic) pets . Cats have adapted to domestication so that each individual, whether stray alley cat or pampered housecat, can change their activity level at will, becoming nocturnal or diurnal in response to their environment or the routine of their owners . Cats normally demonstrate crepuscular behavior, bordering nocturnal, being most active in hunting and exploration at dusk and dawn . </P>

Owls sleep during the day and are awake at night because of their kind of