an out house or out building
they are rodents not animals
i have had them in my room before
they niped my seedlings of at soil level and just left them thier
never had problem with them with mature plants just seedlings
I wouldn't of thought a mouse would be interested in your plants, to be safe you could get a snake to guard them for you or buy a trap humane/lethal depending on preference, the last and probably worst thing to do would be to put down food so it leaves your plants alone, though he might nibble some leaves and get the munchies