As to where to set them, you must find some signs of mink near water, tracks in sand, droppings, or best of all, used holes. Now remember you have to deal with some of the most intelligent but superstitious and shy of animals. I kept one at my house for a while and found him more intelligent than a cat or dog. They get bold and careless some times, but not very often. Their holes are frequently shallow, and they are suspicious of one's presence. The less you frequent the place and tramp about his paths, the better. Avoid the hole if possible.
First choice is to set the trap in shallow water on his runways, sticking up weeds if necessary to make him go over the traps. The next choice is where he goes in and out of the water. Next in dry path and last at his hole where he is the most suspicious of disturbance. Water set is the best and easiest, but even then the trap should be covered with light mud.
On dry land you should leave the place looking as natural as before. At the hole use a small trap, Blake & Lamb is the easiest and quickest set. Remove enough dirt to sink the trap to a level. Set trap with jaws never crossways to the hole. Have jaws rest so that jaws will not tilt if stepped on. Now see that pan is set just about right, not too easy, and now you are ready for the most important part--to cover--so it will stay covered and spring regardless of freezing, thawing, snowing, or blowing, and not to clog the jaws with rubbish. It is too tedious to get the mink over the trap to have something go wrong at the critical moment. I use brown tissue paper or the fuzz from cattails, which I sprinkle with a little fine dirt or rubbish at hand, the chain having been previously staked and hid. All should now be left looking as natural as before, and one's tracks obliterated.
A well set trap will not reveal itself to the game or to any other trapper. A hole set trap should not be approached unnecessarily. Mink will seldom get in the first night, and it takes too long to reset them.
Mink will stay in holes several days if they fear danger. I had one stay twelve days because there was a Stop Thief trap over the hole, but I kept it there because there was a steam visible at the mouth of the hole, and I got her. I have used scent to some advantage, not to draw but to detract the mink's attention, but as to baits I have faithfully tried them all from muskrat to a frog, and I have never known a mink to approach any of them no matter where, when, or how left, except if left by themselves.
In the fore part of the winter I caught about all the males, perhaps because they were bolder. Later I got the females. The largest mink I got stretched 42 inches from tip to tip, and his hide on a five inch board was 24 inches. He was light brown. No. 0 held him by two toes. In fact, I never lost a mink from that sized trap. Those that chewed out were caught up too high.
My experience in trapping is altogether in mink and in a prairie country, and it has always been a great pleasure and very profitable for me, says an Iowa trapper. As I have said, trapping mink is a science which few trappers understand, and can learn only by long experience and close study. Any one taking two or three dozen traps and stringing them out, setting in holes and ditches, can catch a few mink. I know men who have trapped for years and claim to catch lots of fur, but it makes me smile to see how they set them; they simply don't know their A B C's about trapping mink.