they told the hindbrain : the person knocking will , if no one eventually answers , open the door anyway and sidle in , whereupon he will certainly nick any smokes that are lying around , read any correspondence that catches his eye , open a few drawers , take a nip out of such bottles of alcohol as are discovered , but stop short of major crime because he is not criminal in the sense of making a moral decision but in the sense that a weasel is evil - it is built into his very shape .