As columnist Mary Schmich once said, in life, there are certain inalienable truths: prices will rise, politicians will philander, and – I’m going to add one – you can always count on New York for a good old rat story. Today that story is of the Upper Manhattan Chipotle food chain rats, who have been feasting on avocados and burritos – and, by the sounds of it – disturbed staff. The rats seem to have developed the same expensive taste for avocados as many New Yorkers – they liked them s