Learn how to trap them. Then you can either kill & eat them, or pitch them in the bin.
The way things are going, you will soon need to eat them, so be sure to encourage their presence.
"The budget should be balanced, the Treasury should be refilled, public debt should be reduced, the arrogance of officialdom should be tempered and controlled, and the assistance to foreign lands should be curtailed lest Rome become bankrupt. People must again learn to work, instead of living on public assistance." -Marcus Tullius Cicero