PETROKUM Rodenticide 0.005 BB is a rat poison without bait in the form of a bluish box or block. This poison is very effectively used to control all species of rats, including field rats (Rattus argentiventer), bush rats (Rattus tiomanicus), and rat pests that are resistant to other anticoagulants. Petrokum contains the active ingredient brodifakum in amounts as high as 0.005%.