Mouse apocalypse

This year the mouse population is exploding in the Ariège. We 've hardly had any mice for the last 3-4 years but this year it's bonkers. We're catching 3-4 mice every night and the cats are adding to the total. I keep trying to find and block possible entry points, but they keep on coming. At night they are in the kitchen, the utility room, the roof.....chewy on the wood, the insulation. Outside they are everywhere!