I grew up in suburbia. The only thing I knew about ferrets was that they were used in Mary Norton's The Borrowers. And there is remained for many years.
My youngest son now has a friend who goes ferreting. My youngest has been out several times. They catch rabbits. Thankfully, the rabbits have been given off to other people to eat because I am not very good at gutting. My youngest being 13, enjoys the possibility of gore. I have asked if ferrets kill moles but his friend has not been forthcoming about this. He believes the breed is too big. Another friend of my son has a smaller breed of ferret that goes after rats. A distinct possibility.
My son returned home yesterday from ferreting. When asked about the heavy odour, he blithely informed me that the ferrets are going into mating season.
He had to wash his clothes and gloves before going further.
Have decided on point of principle -- do not want ferrets and will stick to attempted trapping of moles.