Formula 'B' Mouse Poison Bait Blocks are formulated with maximum strength Brodifacoum, creating a powerful and fast-acting rodenticide which delivers rapid results. The unique blend of ingredients and multi-faceted design make these Bait Blocks highly palatable to mice, helping achieve rapid eradication of a mouse infestation in your home or business. As well as being ideal for indoor use, these blocks are totally weatherproof so are also suitable for outdoor baiting.