We have mice and rats here as well just started to increase. I use a stack of single traps and also Racumin paste. They completely destoyed the electrics in the workshop and garage and they get into cars and machinery. I now have no compunction using poison. I dont like it but the house would be awash with poo - they get into the beds and wee and poo all over the sheets and chew through plastic containers to get at food and contaminate the sheep feed in the shed. I just leave poison under the house and traps in the house and it soon sorts them out. They also attract snakes into the yard.
I was round at a neighbouring farm eating dinner when a mouse dashed out from under a cupboard and carked it right in front of us.
My mum was visiting and she woke up in the night to the feel of a mouse nibbling on her fingers. These days I have a pretty good strategy to keep them at bay.