Main Entry: cre·pus·cu·lar
1 : of, relating to, or resembling twilight : DIM
2 : occurring or active during twilight
Crepuscular is a term used to describe animals that are primarily active during the twilight. The word derives from the Middle English and French word crepuscule, meaning "twilight". Crepuscular is thus in contrast with diurnal and nocturnal. Crepuscular animals may also be active on a bright moonlit night. Many animals that are casually described as nocturnal are in fact crepuscular. Within the definition of crepuscular are the terms matinal (or "matutinal") and vespertine, denoting animals active in the morning (dawn) and evening (dusk) respectively.
The patterns of activity is thought to represent a response to selection from predators. Many predators forage most intensely at night, while others are active at mid-day and see best in full sun. Thus the crepuscular habit may reduce predation. Additionally, in hot areas, it may be a way of avoiding thermal stress while capitalizing on available light.
I found it very entertaining that almost every pic tied to this word (for at least 8 pages into the google image search) were sunsets: lol. heh. but I did find this cute guy:
Ok - nuf of that I'm going back to either using my insomnia as a tool for cleaning or, sleeping. Probably cleaning. lol.