> Low-light conditions are relatively rich in ultraviolet light, and UV vision is generally thought to be important to nocturnal animals. Clearly there is not

> Low-light conditions are relatively rich in ultraviolet light, and UV vision is generally thought to be important to nocturnal animals. Clearly there is not enough UV light at night to activate the glow in most cases, as otherwise people would notice. Also since it’s actually glowing pink, not sure what this could have to do with UV vision. I wonder why nighttime would be rich in UV light though. I’d have guessed that IR light would be a better pathway to night vision, since warm bodies generate IR regardless of the time of day.