How often the bait should be replaced depends on how much mouse activity there is around.  You should check the Protecta RTU stations daily to start with to see if they are eating all of the bait in a day.  The key to control is to keep enough bait in the station to supply the population around the structure.  The goal is to not have it be empty when mice go inside to look for food.  You may find that you have to replace the bait daily at first but after the population dwindles you will have to add bait much less frequently (1 timer per week or even 1 x per month). Bait should also be replaced if it is insect infested or moldy.

The Protecta RTU Mouse Bait Station is a tamper resistant container that will keep non-target animals from consuming the poison bait. The Protecta RTU does not trap the mouse in any way, the mouse enters, eats the bait and is free to exit. If you would like a covered box that the mouse enters and cannot leave, you do have a couple of options. You can use the Victor Kill and Seal Mouse Trap Model 265. This is a small container that the mouse will enter, be killed and contained. The other option would be to purchase a Protecta Mouse Bait Station and place a wooden snap trap or a Mini-T Rex snap trap inside. With either of these options you would not need to use a poison bait as the mouse will be killed anyway. You can bait the traps with peanut butter (not recommended for the Mini-T Rex), pieces of cereal, bits of cotton or other baits.

The Protecta RTU Mouse Bait Stations are tamper resistant and lock when closed. They are safe for use around pets and children, but bait should always be kept out of reach of children and pets. This kit would be excellent for your mouse problem. The stations are also reusable, so you can use the same ones that you had from last year. You can refill them with bait as needed. How often the bait should be replaced depends on how much mouse activity there is around.  You should check the stations daily to start with to see if they are eating all of the bait in a day.  The key to control is to keep enough bait in the station to supply the population around the structure.  The goal is to not have it be empty when mice go inside to look for food.  You may find that you have to replace the bait daily at first but after the population dwindles you will have to add bait much less frequently (1 timer per week or even 1 x per month). Bait should also be replaced if it is insect infested or moldy.