A brief review of deratization carried out in Budapest (2 million inhabitants) is given. As a result of an extensive eradication project initial infestation level of premises amounting to 331 decreased below 0.5%. Materials and techniques employed for the preservation of a rat free state as well as the method how to determine the size of the remainder of the rat population are described. "Idealized premises" were introduced allowing comparison between rat infestations of various areas. Report on the relationship between rat population and temperature, on the areal dispersion of population and on how re-infestation occurs. Finally, conclusions are drawn based on the favorable results achieved.

In Budapest (population 2 million), 33 out of 100 buildings were rat-infested in the early seventies. Thus general deratization was decreed to cover the whole of the city in 1971 to 1972. As a result of the global eradication method applied, the rate of rat-infested premises could be reduced below 0.5% annually. After control the sparsely occurring rats could freely choose any of the habitats released for settling. The habitats of Budapest most preferred by Norway rats are presented after a wide-ranging investigation carried out over 8 years. Our examination data support and in some cases reveal the requirements of Norway rats living in Central European large cities as regards to the environment as well as their ethological features. This knowledge may help in improving deratization and especially maintenance operations, thus increasing the efficiency of the fight against rats.