Norway rats and house mice may consume a lethal dose in one night's feeding with first dead rodents appearing 4 or 5 days after feeding begins. Ready to use. Reliable, all-weather formula. Multi-edge shape gives rodents gnawing edges. Can be used indoors or out. Can be used alone or in Tomcat Bait Stations. Kills mice & rats. Kills warfarin-resistant Norway rats. Made in USA.