To completely remove rats and mice is a simple but difficult task.  The steps for removing each rodent is the same; the only difference is in the traps used. 

There are four easy steps to follow to remove these rodents:

The first step is inspection.  This is the most important, yet hardest of all the steps.  You will need to do an inspection of your building from top to bottom, including gaps, vents, pipes, roof lines and any other tiny openings you find.  Mice, especially, are capable of entering through holes as small as a dime.  It is crucial to do a thorough inspection.

The next step is to seal all the openings you find.  Rats and mice will chew their way in, so use a material – like steel – that rodents cannot get through.  In the case of mice, use sealants such as silicon or polyurethane, so that the mice cannot smell the former entry hole and try to chew their way in. 

Trapping the mice and rats is the third step.  Once the building has been sealed, you will need to get rid of the rodents that are still present inside.  Wooden snap traps are commonly used for rats and mice and are very effective.  For mice, there are other alternatives such as glue traps and electroccution traps; however, neither of these methods is considered the best.  There are also traps able to catch more than one rodent at a time, but that depends on what you prefer to use.  Do not use poison as an option.

The last step once the problem is solved is to remove all rodent droppings and scents.  Clean and decontaminate each area well.  In the case of mice, they leave behind a scent that can attract new mice.  Cleaning can be done by fogging with an enzyme based cleaner and an atomizer.