Can't you get them sorted from the councils enviromental health office.
I had them years ago and i rang the council, anice chappie came, and he explained if you are putting the poison down, you need to use shinny paper out of magazines and put the poison into a cone if you use newspaper for example they can hear someone is coming they scurry away, but if the shinny paper was used, they hear noises, but they feel safe and just carry on eating the bait, I thought he was crackers, but after a little while he solved my problem.