**4. Norway rats in busy street**

The removal system of garbage is different between big buildings and small buildings. Big buildings of 3,000 m<sup>2</sup> or more in total floors occupied by tenants such as stores, offices and hotels are regulated by the Building Standard Act. In these buildings, garbage is treated by building management companies. On the other hand, small buildings are out of regulation, and garbage in these buildings is usually kept in plastic bags and put along roadside (**Figure 3**). Accordingly, small buildings supply Norway rats with food sources, and the rats have become big problems in busy streets.

**Figure 3.** *Garbage in plastic bags along roadside, and a Norway rat attacking such bags.*
