This month at the National Zoo in Washington, D.C., seven species—including sloth bears, clouded leopards, Asian small-clawed otters, and two kinds of pandas—will come together in the Asia Trail, a new habitat constructed just for them. For the past five years curators have been watching the animals' every move and charting their likes and dislikes. Coldphobic leopards will have a heated tree to lounge on. Pandas, who prefer things cooler, will get to frolic on chilled rocks after grazing on acres of bamboo. Nearly every traditional idea of zoo design has been turned on its head, but the most significant change is that the animals are no longer fed in the deep recesses of the exhibit, away from visitors, but in full view. "In essence we brought the back of the display to the front," says Susan Ades, who manages the exhibits. "You'll see animals demonstrating their natural behavior." At 3001 Connecticut Ave. N.W.; 202-633-4800; nationalzoo.si.edu.