From the text:

Eventually, many of them became monks themselves. This would have been the usual course for someone who met with misfortune as Crane-man had, and Tree-ear wondered why he had never asked the question before. Crane-man looked almost displeased for an instant; then his lips curled into a sheepish smile. "Ah. There is a reason, but it is a foolish one, and would become more so in the telling." Tree-ear waited. "Psshh," Crane-man said at last. "It is a worse foolishness to do something foolish and then to be unable to laugh at it later! A fox, then. It was a fox that kept me from the temple." "A fox?"