I wrote back in February about White-footed Mice living in the treetops at the Koffler Scientific Reserve, in King Township. Well, my naturalist-training classmates and I were back at it again last week. We went on another hike with Dr. Monika Havelka, of the U. of T., in search of another White-footed Mouse. Finding the critter was easy enough. It was another matter when it came to measuring him, determining his sexual maturity, and putting an ID tag in his ear. But the Doctor had lots of experience and things went routinely for her. Her final item of research was to facilitate the tracking of of this little mouse's comings and goings by coating him with fuchsia-coloured powder. The powder trail that the little guy leaves behind is readily picked up by a UV light source, and is a valuable tool in research on this small mammal species. The powder, by the way, is not harmful to the mouse and wears off in a few days. Until that happens, though, he probably looks like a rock star to his buddies.