![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
In general, birds have an additional ultraviolet pigment in their cones and many more cones than we have. Furthermore the visual pigments that would be similar to ours span different wavelengths. Their visual experience is richer than our own in ways impossible to describe or understand. ... When a mouse is being hunted by a hawk, it will often urinate out of fear and to make itself as light as possible for escape. Mouse urine radiates ultraviolet and that actually helps the hawk follow the mouse trail. Fresher urine radiates more ultraviolet light. The ultraviolet arrow will point to lunch for the hawk.
-- Sully's Dish
