In 2011, 75 tonnes of poisoned bait left just 60-80 rats alive; they rebounded

Conservationists attempted a large-scale rat eradication on Henderson Island in 2011. About seventy-five tonnes of poisoned bait were spread across the remote South Pacific island. However, a small number of rats survived the intensive campaign. Within two years, the rat population had recovered significantly to former levels. This event underscores the difficulty of achieving complete eradication and the resilience of invasive species.