Scientists Say: Nocturnal and diurnal | Science News for Students

Scientists Say: Nocturnal and diurnal

Some organisms prefer the night and others the day
Apr 30, 2018 — 6:30 am EST
eagle owl

Owls, such as this Eurasian eagle owl, are nocturnal and prefer to hunt at night.

Aishath Boskma/istockphoto

Nocturnal (adjective, “knock-TER-null”)

This is a word used to describe an organism that is most active at night. Nocturnal animals include mammals such as bats, cats, opossums, rats and mice. And then there are the owls that hunt down those rats and mice. Many kinds of insects are also nocturnal. They play an important role in pollinating plants that open their flowers at night.

Diurnal (adjective, “die-ER-null”)

This word describes a creature that is most active during the day. Many of the species we see daily fall into this category. Robins, eagles and sparrows are diurnal. Insects such as bees pollinate the flowers that bloom in daylight.  And of course, no matter how late a person might like to stay up, humans are actually a diurnal species.

In a sentence

The lights diurnal humans put up to ward off the night can keep nocturnal bugs from pollinating plants.

Check out the full list of Scientists Say here

Power Words

(more about Power Words)

bat     A type of winged mammal comprising more than 1,100 separate species — or one in every four known species of mammal.

birds     Warm-blooded animals with wings that first showed up during the time of the dinosaurs. Birds are jacketed in feathers and produce young from the eggs they deposit in some sort of nest. Most birds fly, but throughout history there have been the occasional species that don’t.

bug     The slang term for an insect. Sometimes it’s even used to refer to a germ.

diurnal     An adjective for some activity that is done during the day, or some organism that is active during the day.

insect     A type of arthropod that as an adult will have six segmented legs and three body parts: a head, thorax and abdomen. There are hundreds of thousands of insects, which include bees, beetles, flies and moths.

mammal     A warm-blooded animal distinguished by the possession of hair or fur, the secretion of milk by females for feeding their young, and (typically) the bearing of live young.

nocturnal     An adjective for something that is done, occurring or active at night.

organism     Any living thing, from elephants and plants to bacteria and other types of single-celled life.

species     A group of similar organisms capable of producing offspring that can survive and reproduce.