Remove Mice from Your Pole Barn
Purchase mouse traps. There are different types of traps on the market: those that kill mice and those that simply trap them so you can set them free. Decide which you would rather use and purchase several.
Follow the instructions on the traps, which usually require a bit of food to lure the mice. Place them in several different locations around your pole barn, particularly in areas where you notice large amounts of droppings. Check the traps daily and reset them or buy new ones when needed.
Search for areas that the mice are using to live. You will find "bedding," which is usually made of items they have found around the area, such as cotton from clothes, lint, thread or other soft items. You may also find foods stored in their living environment. Remove the bedding and foods.
Vacuum all areas that have evidence of mice, being sure to vacuum up all droppings. Spray the areas with a disinfectant and wipe up visible urine.
Purchase enough Z-shaped flashing from your local hardware store to cover any opening crack around the bottom parameter of your pole barn.
Loosen the bottom row of screws holding the skin of the pole barn to the base boards. Slip the long flange of the Z-shaped flashing under the skin until the step is secure. Secure with 1" screws. Do this around the entire open parameter, completely closing it off.
Search the pole barn for holes, particularly in the corners or other areas that it may not be completely closed off. Fill the holes with spray foam insulation, which expands to fill the entire gap. If the holes are large, stuff them with stainless steel wool, which rodents cannot chew through.
Make sure you have enclosed the barn and closed off all openings.
Purchase a couple of fake barn owls from your local hardware store. Many of these are motion-activated and will make noise or flash the eyes when an animal scurries across their path. Place these in areas where you suspect mice find their way into the pole barn.
Continue to check the mouse traps daily, as many mice may be locked inside. Remove them promptly and reset or replace the traps until you have not caught any mice for at least a month.