The breakfast buffet spread at the Ah Meng restaurant in Sin­gapore Zoo is, of course, lavish, but surely that alone couldn&rsquot have accounted for the frisson of excitable energy that buzzed through the diners that morning. And it wasn&rsquot just the chil­dren who appeared to have overdosed on a sugar-high energy drink even the adults were all animatedly atwitter. Clearly, something mischievous was afoot...