Controlling invasive species often involves killing large numbers of animals to protect native ecosystems, raising complex ethical questions about welfare trade-offs.
Invasive species control creates a genuine ethical dilemma: each possum, rat, or stoat killed is an individual animal capable of suffering, yet inaction allows the suffering of many native animals through predation. Control methods vary dramatically in humaneness — 1080 poison causes death over hours, while snap traps cause rapid death. The welfare of invasive animals killed in control programs is a legitimate consideration that should inform method selection even when the necessity of control is accepted.