Havoc XT 2nd generation anticoagulant blocks. Features Brodifacoum which is the strongest anticoagulant rodenticide available. Combines mixture of highly attractive bait ingredients along with patented food processing techniques. Controls Norway rats, roof rats, and house mice. May kill in a single night's feeding. Weather resistant with a unique shape that makes it easy for rats and mice to gnaw on. For use in and around agricultural buildings only. 8 pound resealable bag, approximately 182 blocks.