A team of researchers from the University of Wisconsin-Madison and the Smithsonian Institution has discovered a dense layer of biogenic high-magnesium calcite in the exoskeletons of major workers of the leaf-cutter ant Acromyrmex echinatior; they’ve also found that this armor accumulates rapidly as ant workers mature and that the biomineral layer is continuously distributed, covering nearly the entire integument. Their paper appears in the journal...