Nature’s beauty can originate from the most unlikely places. Take leech cocoons, the sacks in which leeches lay their eggs. They have an incredible solid-foam surface, as the image below shows: A team of researchers at Rutgers University, Camden (and one scientist from Turkey) took a look at these structures to figure out how they formed, and why they look the way they do. And why did they do that? “Because it’s fun,” said the study’s first author William Saidel.