We got a telephone call from a gentleman over in Bolton, MA who had a house built in the 1800. He had some fear in his voice, his wife really wanted to get rid of these mice. They were tired of regularly having an exterminator come in to get rid of the mice. The exterminator actually suggested to him that he have someone come in and take care of the basement. There were holes in between the stones in the foundation; this was an old house. In addition letting in the mice, the holes in the foundation also let in cold air, water, and moisture.
We put sharp metal mat pieces in these holes and then repointed, or put mortar back in, and stopped the mice problem.