I recommend the No. 1 trap for this animal and those of medium strength of spring only, as the opossum's foot and leg is tender, and if the bones are broken the animal is likely to escape. They do not struggle much, however, and comparatively few escape from the traps.
I set my traps in the thick woods, usually in the gullies also along the edges of the woods, along fences, etc. The opossum is possessed of no cunning whatever, and no special care is needed in setting the traps if this animal alone is expected, however, it is always best to use care in setting for the most stupid animals, as one never knows what animal may pass that way. Whenever possible I place the trap in a natural enclosure, such as a hollow in the side of a stump or tree, a hollow between two spreading roots, an opening among rocks or in a hollow log. Failing to find any such place I construct a small enclosure of stakes, bark, stones or pieces of rotten wood, whichever is most convenient, and set the trap in the entrance nesting it down and covering with whatever is found nearby.
The trap may be staked, stapled or fastened to a clog. For bait I use rabbit, fowl, muskrat or small birds of any kind. Bait may be fresh or tainted as the opossum is not particular. I have heard of many fancy sets and baits and have given some of them a trial, but find the method given above to be the most satisfactory.
Opossums will sometimes be caught in traps set for skunks, foxes and other animals and there are probably more of them caught in such sets than in any other. They may also be caught in wooden traps.
I have caught these animals in traps set on logs spanning the streams, also at the entrance of the dens, but if I were setting many traps for opossums I would use the above method mostly. The opossum makes a wandering, aimless sort of trail, quite broad for an animal of its size and the toes are turned outward in walking. The footprints of the average opossum will measure about one and one-fourth inch in diameter--that is, the front foot--the print of the hind foot being from one-fourth to one-half inch larger.