This essay delineates the material and conceptual limitations of two prominent ways of figuring the relationship between humans and harmful beings: narratives of eradication and entanglement, respectively. Ecological concern about the legacies of 20th century attempts to eradicate life deemed harmful to humans (such as the damage fostered by DDT and over-uses of antibiotics), coupled with the declines in the efficacy of major medical and chemical techniques for eradicating beings deemed harmful, mean that exterminism is increasingly seen as both ethically undesirable and materially impossible. At the same time, it is insufficient to fall back on narratives about the ontological inevitability of entanglement with nonhumans, because the harms – for humans and other species – that are posed by particular relations are tightly bound with socioeconomic inequalities and asymmetries in power. Through situating contemporary viral relations in relation to existing literatures focused on pests and parasites, the essay argues that harmful beings are not just exceptions that can be worked around and ultimately accommodated within relational ethics. Instead, harmful entanglements offer more fundamental provocations, forcing attention to the question of how to create more liveable worlds through situated acts of distancing without descending back into narratives of eradication.