The Tomcat Mouse Killer Refillable Bait Station - Advanced Formula controls mice with an advanced formulation bait block that is more attractive to house mice (compared to our Tomcat Mouse Killer Child & Dog Resistant Refillable Station [EPA Reg. No. 90780-10]). This Tomcat mouse bait station can be placed indoors or outdoors and it's resistant to weather and tampering by children and dogs. Each block of bait can kill up to 12 house mice (based on no-choice laboratory testing) and each package contains six blocks. Bait stations with mouse poison should be placed beside burrows, along walls, behind kitchen appliances, inside cabinets, in garages and basements, and along the exterior of the home. If more than one station is being used, place them at 8- to 12-foot intervals. Mice will likely eat a small portion of the bait and then leave the station. The Tomcat Mouse Killer Refillable Bait Station - Advanced Formula has a clear cover to make it easy to monitor the bait block. When there is no more bait in the station, easily refill it with one of the provided bait blocks (only use one at a time).