I'd try and identify where they're coming from (and what Andy says is quite true, they can squeeze through the smallest of holes) and pour any amount of bleach or similar in and around the area. Use things you may have in the house, rather than buying fancy repellents which don't seem to work.
I'd try and identify where they're coming from (and what Andy says is quite true, they can squeeze through the smallest of holes) and pour any amount of bleach or similar in and around the area. Use things you may have in the house, rather than buying fancy repellents which don't seem to work.