Understanding the reasons for disagreements about conservation issues can facilitate effective engagement between the people involved. Invasive species are often central to such debates, with researchers and members of the public frequently disagreeing about the nature and magnitude of problems posed by the invaders, and the best ways to deal with them. The spread of non-native cane toads (Rhinella marina) throughout Australia has stimulated research on toad impact and control, and has mobilized local communities to reduce cane toad numbers through direct action. Biologists and community groups have disagreed about many toad-related topics, providing an instructive case history about impediments to consensus. Debates about the ecological impacts of cane toads mostly reflect poor communication of available research results (ie scientists have been largely unsuccessful in transmitting their findings to community groups), whereas disagreements about toad control reflect an information vacuum about the effectiveness of alternative methods, such as trapping, biocontrol, and predator training to induce toad aversion, among others. Many other disagreements have arisen from the differing motivations of scientists and community groups. Although the debates are superficially about evidence, the deeper divergence reflects differing social pressures, the ways that information is transmitted, and how people evaluate the validity of information.