I've mentioned before that my teenage son Nick is a HUGE animal lover. He loves to read any animal-related nonfiction that he can get his hands on, and often shares information he's learned with the rest of us. Two words that we hear quite a bit at our house are nocturnal and diurnal.
Nocturnal [nok-tur-nl] is an adjective meaning "of or pertaining to the night". When talking about animals, it refers to those that are active at nighttime -- bats, owls, wolves, and more.
Diurnal [dahy-ur-nl] is the opposite of nocturnal. It is also an adjective, meaning "of or pertaining to the daytime". Diurnal animals (most birds, for example) are active by day.
Here are a few sample sentences, using the words:
Because they are nocturnal,
bushbabies have very large eyes;
this feature helps to compensate for the
lower levels of light during their waking hours.
Have you ever been on a nocturnal hike,
with only the moon and a flashlight to light your way?
Her diurnal routine always begins with a shower.
At sunset, diurnal creatures can usually
be found settling into their nests and burrows.
What other things can you think of that are either nocturnal or diurnal?