Smithsonian National Zoo's giant panda Mei Xiang snuggles with her cub in her den at the National Zoo in Washington, in this photo tweeted on September 9, 2013. Keepers are starting to do some ... more 
Smithsonian National Zoo's giant panda Mei Xiang snuggles with her cub in her den at the National Zoo in Washington, in this photo tweeted on September 9, 2013. Keepers are starting to do some training with Mei Xiang in her den, according to the @NationalZoo twitter account. REUTERS/Smithsonian's National Zoo/Handout via Reuters (UNITED STATES - Tags: ANIMALS) ATTENTION EDITORS - THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. IT IS DISTRIBUTED, EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS. FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS less 
1 / 23
Reuters | Photo By HANDOUT / REUTERS
Mon, Sep 9, 2013 10:30 PM EDT