What trick did cratchit's family play on him as he entered the house?

When Scrooge enters at the Cratchit's house he starts to understand that Bob is a human being and that Bob has a family to support. Scrooge sees Tiny Tim and ask to the Present Ghost if the boy will die and the ghost say that he could if his future didn't change. Mrs Cratchit's at the table curses Scrooge but her husband reminds her that is Christmas and make a toast wishing that he has a Merry Christmas and to be happy. Not only in Cratchit's house but Scrooge passing by the town can se the happiness in every house.