Neogen Havoc Rodenticide Place Packs are a second generation anticoagulant rodenticide formulated for effective control of Norway rats roof rats and house mice. This superior single feed bait may cause death within four to five days after a lethal dose is consumed and can eliminate rodents in as little as one nights feeding. The highly palatable formulation combines an effective active ingredient with a special blend of attractive bait materials using patented food processing techniques for reliable results.