In Helsinki last year the warm autumn followed by a mild start to the winter resulted in a record number of rats. And the annual number of complaints recorded by the City of Helsinki's Environment Center was 86, which is over 40 percent more than during the five previous years on average. But meanwhile nobody knows exactly how many rats there are in Helsinki. The estimates vary between half a million and a million. For the rodents to breed make it easier a warm summer, a long autumn, and a mild winter. Typically, in the neighborhood of grocery stores and restaurants rats feel at home, if the owners do not take care of their garbage and keep the environment clean. Besides, rats are able to benefit from the feeding places of birds in parks and cemeteries. And today, for pest control are responsible property and landowners themselves.