But there’s another major category for activity for animals and that’s crepuscular. Crepuscular, a word drawn from the Latin word for “twilight,” is a term for animals that are active primarily at dawn and dusk. There’s a very smart reason for picking these dimly lit in-between hours to be active: crepuscular critters are avoiding predators.

What Does Crepuscular Mean? This simply means that an animal is mainly active during twilight (when the sun is setting) and dawn (when the sun is rising). Animals may choose this type of time to be active for a number of different reasons.