Leaf-cutter ants forage for leaves (A) that they use to cultivate a fungus in specialized gardens (B) within their massive colonies (C). Sugar composition analysis of the plant biomass from the top and bottom layers of multiple fungus garden chambers shows an overall decrease in average content for many of the components of hemicellulose (D) and cellulose (E). In contrast, lignin (F) exhibited no change in average content. Error bars in graphs are standard error of the mean. The asterisks indicate a significant decrease in overall average content between top and bottom samples (two-tailed paired t test, P<0.05). [Photo credits: river of leaves, used under the GNU Free Documentation License CC-BY-SA-3.0,2.5,2.0,1.0; exposed fungus garden, Jarrod J. Scott/University of Wisconsin-Madison; concrete nest, Wolfang Thaler].