The casting of ‘invasives’ as ecological villains has long been backed by scientific and political consensus. Yet as species increasingly move into unfamiliar regions, a favouritism towards natives is growing harder to defend. The traditional approach of trying to stop invasions and eradicate successful invaders isn’t just costly and often ineffective. It may be entirely the wrong approach, if we’re concerned about the environment. While some invasive species are truly harmful and need to be fought, others are a healthy ecological response – they’re part of how the biosphere is adapting to humanity’s environmental impact.