Two young male Sumatran tigers play in a new $19.5 million Tiger Trail at the San Diego Zoo Safari Park in San Diego's San Pasqual Valley May 21, 2014. The soon to open exhibit will house six tigers and features waterfall feed ponds, rocks for climbing and tall crass for catnaps. REUTERS/Mike Blake (UNITED STATES - Tags: ANIMALS SOCIETY TPX IMAGES OF THE DAY)