Connect with us: http://www.facebook.com/sandiegozoo http://www.twitter.com/sandiegozoo http://www.instagram.com/sandiegozoo http://www.pinterest.com/sandiegozoo http://www.sdzoo.tumblr.com/ The San Diego Zoo's panda cub, Xiao Liwu, was eager to play with a plastic ball during his 18th exam. Panda keepers gave the cub the ball to test his coordination and encourage him to play with new objects. http://www.sandiegozoo.org/pandacam