Entomologist Paul J. Johnson of biology and microbiology and his graduate student, Laura Winkler, are looking at ant diversity to evaluate the health of reconstructed grasslands. They are comparing prairie remnants in the same region with areas that had previously been cropland or pasture but have now been restored to native grasslands for anywhere from one to four years. They refer to ants as "ecosystem engineers." They expect that ant populations will be more diverse in those areas which have been restored for the longest time. An AP article written by Lance Nixon of the Capitol Journal entitled "Research shedding light on South Dakotas ants has the full story.