Bingowings said:

Mice don't understand the difference between a house and any other shelter, you couldn't invite them into your house if you wanted to because they don't understand your language.

Hopefully that was just your attempt at being humorous, but obviously when I said "invite" them into your home, I didn't mean speaking to them and inviting them over as a guest (I feel stupid feeling like I have to explain this). What should go without saying was that I meant bringing them into your home on your own, as opposed to them finding their own way in without you wanting them to.

Bingowings said:

Living near a river in central Scotland we have midges but we also have insect repellent, yeast extract and beer.

Insects (especially the bity kind) tend to avoid beer drinkers/Marmite eaters because the yeast.

Wow, bugs must not be too bad in central Scotland then. I've been to plenty of places where no amount of beer or DEET is going to protect you from much of anything.