(Farnam) Just One Bite EX Bait Blocks kill Norway rats, roof rats and house mice. Rodents usually consume a lethal dose in just one feeding. Just One Bite EX contains bromethalin. Due to bait's stop feed action, rats and mice cease feeding after consuming a lethal dose. Ideal for addressing and cleaning out heavy rodent infestations. Death is delayed 2 or more days after consumption. 0.5 oz. bait blocks.