Hamelin is a sleepy town in Germany. It seems to gentle and so quite， you would think that life ran forever as peacefully as the river running past the walls. But there was a time long ago when Hamelin was over-run by rats， and greed and treachery brought about a terrible tragedy.
The rats were like the plague. They appeared suddenly and crept into every corner of every house in the town. They were large and black and fierce. They had whiskers as stiff as straw and tail as long as your foot.
All night long they squeaked and chattered and scurried and scratched. There was not a floorboard， not a cupboard， not a wainscot that they had not gnawed through. Fat rats made their nests in the horsehair mattresses. Hungry rats went hunting in the family larders. There were rats in people's boots in the morning. There were rats in their pockets and in the children's satchels. They nibbled the noses of the babies in their cots.
'Leave it to me！' said the mayor， when the council met in the old town hall. 'I'll personally provide one hundred cats to rid us of these rats.
The rats chased the cats right out of town.
'Try dogs，' said one of the councilors.