Some images here hint at the methodology: https://phys.org/news/2018-06-scientists-bees-concept.html https://phys.org/news/2018-06-scientists-bees-concept.html

Some images here hint at the methodology: https://phys.org/news/2018-06-scientists-bees-concept.html https://phys.org/news/2018-06-scientists-bees-concept.html The number of ink marks (a discrete quantity) was varied independent of the mass of ink; the bees aren't just gravitating to the least inky paper.