They are strictly nocturnal and start flying after nightfall, then possibly stop some hours before dawn.
The bush rat is strictly nocturnal and is active year-round.
Some daytime movement has been observed, suggesting they are not strictly nocturnal but crepuscular.
The lesser bilby, like its surviving relatives, was a strictly nocturnal animal.
It was a strictly nocturnal animal which led a solitary lifestyle.
Black-footed cats are solitary and strictly nocturnal, thus rarely seen.
The species is secretive and strictly nocturnal, and mates on land.
Nighthawks are less strictly nocturnal than many nightjars, and may be seen hunting when there is still light in the sky.
Unlike most members of their family, flying squirrels are strictly nocturnal.
Although some species are strictly nocturnal, females are often active during the day.