In Germany, rodent control in the non-agricultural area relies heavily on the use of anticoagulant rodenticides, i.e. baits containing active substances that inhibit blood coagulation. Although these compounds have unacceptable effects on the environment, they were authorised under the European Biocidal Products Regulation. However, their authorisation is subject to strict risk mitigation measures (RMM) such as the restriction of use to (trained) professionals or setting mandatory instructions for use. These RMM drove many discussions and raised numerous questions among manufacturers, users and industry in Germany. The German Environment Agency has therefore compiled answers to frequently asked questions (FAQ) on the authorisation and use of anticoagulant rodenticides in this document. The 4th edition provides latest information about the emerging environmental issue of anticoagulant rodenticides in fish and dedicates an entire chapter to rat control in sewer systems.