Researchers hope Guam's snakes take the bait. Micha Klootwijk/iStockPhoto.com hide caption

itoggle caption Micha Klootwijk/iStockPhoto.com

Bob Adams is a lab animal veterinarian at Johns Hopkins University. Maggie Starbard/NPR hide caption

itoggle caption Maggie Starbard/NPR

This image shows a human glial cell (green) among normal mouse glial cells (red). The human cell is larger, sends out more fibers and has more connections than do mouse cells. Mice with this type of human cell implanted in their brains perform better on learning and memory tests than do typical mice. Courtesy of Steven Goldman hide caption

itoggle caption Courtesy of Steven Goldman