They are a closely related offshoot of humanity, one that has become nocturnal.

Others frogs have adopted behaviours to conserve water, including becoming nocturnal and resting in a water-conserving position.

Maras may even change their habits from coming out in day to becoming nocturnal, simply to avoid social interaction.

Alan kept silent through those months, becoming almost nocturnal, refusing to talk to any brother who dared to talk to him.

Perhaps she had become nocturnal.

At lower altitudes, it may be found at any time of the day, becoming increasingly nocturnal as daytime temperatures rise.

The peregrine falcon is becoming more nocturnal in urban environments, using urban lighting to spot its prey.

Therefore, in warm weather, they change their patterns of activity, becoming crepuscular or nocturnal.

Where they are hunted frequently, bears become purely nocturnal.

Like anyone anywhere who didn't bear a mark of loy-alty to Carpathia, Albie had become nocturnal.