In article ,
Timothy Murphy wrote:

We were away from our house for a couple of months,
and when we came back there were hundreds of mouse (or rat) droppings
in just 2 rooms.
To get into one of the rooms, the mice had to climb up a 2 metre wall.
They got into the other room through an air-hole.

I'm wondering if there is any way of stopping them climbing a wall?
It's a reasonably smooth plastered wall (outside).

Yes. Metal flashing (ideally not lead - it's too soft). Either
4" flush and vertical or 2" sticking out and down. If it is rats,
you need three times those lengths. Mouse droppings are rice
grain sized - rat ones are much bigger.

Also, is there anything better than mice traps to dissuade them?
They came through a garden, and I wouldn't like to put anything down
that could harm other animals.

Poison. Put it inside the house.


Regards,
Nick Maclaren.