Our study, comprising interviews and ethnographic observation, examines the human-rat conflict that arose in two urban allotment gardens in Helsinki as a case of multispecies negotiations. We view the rats’ presence and actions in the gardens as political claim-making, to which humans respond. Through these interactions, humans become attuned to the rats’ needs and build socio-ecological knowledge that is vital for more-than-human coexistence. As a result, the gardeners and the rats co-create an implicit code of conduct that defines the conditions of peaceful coexistence. We propose that the code of conduct framework is a useful tool in recognizing pathways towards solutions that achieve multispecies justice.