I live rurally and I'm used to wildlife and have occasionally seen a field mouse in the house. Used traps all fine but recently it's relentless and they are in my kitchen. Mouse droppings on one side of the kitchen so I can visualise their run if that's the right word but I can't find where they are getting in. Trapping them all the time but still they keep on coming. My kitchen is spotless, but it's starting to seriously get on my nerves. I'm cleaning and cleaning. No sign of them anywhere else in the house. So I'm guessing they are getting in from outside, kitchen is in an extension but I can't find their way in. Any advice before I completely loose it, shall I put poison down?