It makes more sense when you realize this word came from the Latin word crepusculum, meaning twilight.  In zoologogy, it means an animal that appears or becomes active at dawn and dusk.  

1 hour ago, Valkyrie said:

Who else read this as craptacular? 😬😝

Actually, when I first saw the word I thought it said creepuscular.  And seeing it refers to animals that come out at dusk and dawn, some of them can be very creepy.  

Not to be confused with craptacular, often used to which describe the play of New York pro football teams and Disney movies.

1 hour ago, Cia said:

My son's leopard gecko and my daughter's ball python are both crepuscular, and they technically don't rely on having UV light to stay healthy like other reptiles kept in captivity. We have automatic lighting systems set up for them to mimic a sunrise/sunset but keep it consistent rather than follow winter's early nights since that helps keep them in a healthy sleep pattern since they both tend to "burrow" in one of their hides during the day above their heat mats and below the lights on the warm sides of their tanks. They both also eat right about 8 PM when they're fed. 

If you hadn't stated which child had which pet, I might have suspected it was the other way around.  I just hope the gecko doesn't become a snack for the python at some point.