Humans think in dichotomies, and one of the most potent of these in conservation is ‘native’ versus ‘exotic’, whereby native species are considered good and exotic species bad. This dichotomy is generally useful but leads to some confused thinking. Dingoes are often claimed to be native dogs when they should be considered exotic. Many native animals, including threatened species, are growing dependent upon exotic plants and animals, and this dependency calls into question the presumption that exotic means ‘bad’. Conversely, many native species behave at times as pests. The native-good, exotic-bad dichotomy is under attack from many people who do not want to see exotic pests controlled. Biologists should be thinking more about these issues.