Why was warfarin used to control the rat population in the past?

Warfarin was used to control rat populations because it is an effective anticoagulant that induces hemorrhagic death in rodents. When ingested, it interferes with the synthesis of vitamin K-dependent clotting factors, leading to internal bleeding. Its effectiveness at low doses and the fact that it could be used in bait form made it a popular choice for rodent control. However, concerns about resistance and non-target species exposure have led to changes in its use and the development of alternative rodenticides.