Rats and mice are opportunists that have a propensity to that find their way into places they don't belong. They are creatures of comfort and will enjoy your work and living spaces, if you let them!
The first order of business is to get those rascals out! This can be accomplished with several effective management means. Then it's important to look at how and why they found your property inviting. Are there sources of food and water? Are there sanitation issues? Does the building have access points that allow the rodents the ability to get inside? These are all issues that Pestgon Inc. can help you solve.