19th-century ships accidentally brought mice to islands 30 miles off San Francisco; they later reached densities of 1,270 per hectare and began reshaping the seabird ecosystem

The Farallon Islands are grappling with an overwhelming invasion of house mice, significantly disturbing the delicate ecological system. These rodents threaten the survival of native wildlife, with burrowing owls preying on them and subsequently impacting the vulnerable Ashy storm-petrels. A new eradication initiative involves dropping rodenticide bait from helicopters, driving efforts to restore the natural balance of this unique ecosystem.