Established invasive species pose a difficult management problem because over time they form complex interactions with local species and can replace the ecological role of lost natives. Pest removal to mitigate an impact on one target may therefore have unexpected impacts on other elements of the ecosystem. In this talk we explore the impacts of introduced black rats (Rattus rattus) living in peri-urban bushland around the harbour foreshore of Sydney, Australia. Black rats were introduced to the area 220 years ago and the local small mammal fauna are locally extinct. We conducted a 3-year replicated black rat removal experiment on 16x 1ha plots to examine the impacts of black rat predation on (i) artificial bird’s nests, (ii) populations of garden skinks (iii) invertebrate populations, and (iv) pollination of Banksia inflorescences. We found that black rat removal lead to greater nest survival and higher skink numbers, indicating rat predation was an additive source of mortality. However, the magnitude of impacts on skinks was akin to that of a native predator rather than an exaggerated impact typical of alien predators when benchmarked against known effect sizes. Rat removal led to increases in spider abundance, but also an associated decrease in the diversity of invertebrates in lower trophic levels. This result supports a role for black rats as an apex predator of invertebrate communities. Finally, black rat removal led to a decrease in seed set in Banksias. Together these results show that removal of long-standing pests with complex interactions leads to complex outcomes.