We know that all wild furbearers are interested in holes. These holes can be up in a tree, in a log lying on the ground, in a stump, at the base of a tree or boulder, or under a flat rock. These holes can be small; the size of a mouse or large insect hole to the size a bear would use for a den. I have seen holes in agricultural fields, in fence rows, on hillsides, even in lawns and under buildings.

All of these mentioned holes had their beginning by being dug by an animal. Oh yes, some birds will make holes in tree trunks and large limbs, and in the sides of some buildings. There are some birds that will make holes to live in along the steep banks of streams or cliffs. Some animals will even dig holes underwater.

Holes that were dug by animals have probably been used by trappers since the invention of the foot-hold trap. What better place to put a trap than where the animal is actually living?

I can only assume that some early thinking trapper got the idea of making a hole instead of looking to find one an animal had dug. This early trapper caught animals at the "man made" hole. It probably wasn't much later when these early trappers got the idea of putting some kind of bait in the hole that the target animal would be interested in. This increased the trapper's catch over the hole with no bait. The dirt hole was born!

Then he learned to make the holes of different diameters and depths. Another thing he learned was quite often some of these man made holes didn't get any action from the animals, while other holes he made produced very well. Where these holes were at a good location the animals visited them.

The use of this set was passed down from father to son for generations. The use of different tools for digging the hole was gradually improved upon.

Setting traps in underwater holes was a problem in most cases. Then the trapper probably thought; "If I can make a hole on land and animals will investigate it, maybe if I dig a hole into the stream bank at water level, these water-related animals will come to it." The pocket set was born.

Back 50 years or more ago the dirt hole set was a well-kept secret. Now it is common knowledge, and anyone wanting to learn about it can find this information in print in the many books written on fox or coyote trapping. A more recent source of this information is the videos put out by some trappers.

I have noticed that most (not all) trappers have only one way they make their dirt holes. All of their dirt holes look alike. As my trapping expertise increased through the years, I learned to make each of my dirt holes in an area to look and smell different.  Some will have a large dirt pattern in front of the hole, while others may have a small mouse size hole. The dirt pattern at this small hole is blended in with the surroundings.

Some of my other dirt holes aren't round, they look very much like an animal had dug them. It resembles a narrow trench like affair. This is how fox, coyotes and dogs dig. It looks more natural than a round hole.

Some of my dirt holes are constructed to fit the bait or lure I will use at it. The small mouse hole will have the smell of mice in the hole, with a blended in trap guarding the approach to the hole. The bait I use made from larger rodents such as groundhogs will have a larger hole and a wide dirt pattern. This seems more natural, and works well for me.

Then there are the curiosity smells. Some of these smells that create curiosity to the wild canines are: skunk, civet, valerian,  castorieum, mink musk, asafetida, and many others too numerous to mention. Most of these curiosity smells are not used by themselves, but are used in formulation of lures and baits.

It was during May, June and July when I spent many hours in the heat with the flies, bugs and mosquitoes spying on families of fox. I did this for four straight years. I wasn't given any "grant money," and I wasn't paid for doing this observation. I did it on my own because I wanted to learn more about the habits of the fox.

After the fox pelts were past their prime for the season, I would then spend time and put on many miles following their tracks in the snow. This taught me the places they liked to hunt, and the places they preferred to rest during daylight hours. I saw how they hunted rabbits in pairs, how they hunted birds and mice. I found where they had buried food when the hunting was good. I also saw the sign in the snow where they had dug up cached food. I saw the kinds of things they preferred to urinate on in their travels.

All of this surveillance and tracking helped me to become a better fox trapper. By applying the things I had learned, it helped me to pick the best locations for my sets.

One of the most important things I had learned by doing this surveillance and tracking was:  Fresh dirt to a wild canine means food. Rodents of all kinds dig into the earth for food or to make their dens. The wild canines use these large and small rodents for food.  So when fresh dirt is seen or smelled by the fox or coyote, food is what pops into the animal's mind. I will accommodate the animal by having food, natural food, in the hole and a trap concealed in the fresh dirt in front of the hole.

Another smell used by trappers at dirt holes is the natural smell of the target animal. This smell can be urine, or there are certain glands that can be taken from the animal and compounded into a lure. This type of a lure is called  "gland lure."

With the use of baits, curiosity smells, and gland lures, the dirt hole can be made attractive to the wild canines and other animals. However, most experienced trappers do not use all of these smells at one dirt hole set.

I had been using the dirt hole for a number of years and had reached kind of a plateau as far as my catch went. Then I spent more time studying the fox during the off season of trapping.

With the use of good binoculars and a good spotting scope I have spent many hours day after day watching a den of foxes from a distance. I saw the parent fox bring in food to the pups. I watched these parent fox bury food for later use. I also saw them dig up this cached food.

I watched the pups play and have their mock battles. When food was delivered to the pups, it was the strongest and most aggressive pup that got the most. After eating its portion, this dominant pup would then take the food from its sisters and brothers. While this was happening the parent fox would sit idly by and watch, not getting involved in the food squabble among the pups.

Another thing of importance I have learned was; when a fox buries its food, it will not urinate on the place the food is buried.  The only time a fox will urinate at a hole is after it had dug up the food that was cached there. If this food was found by another fox other than the fox that buried it, sometimes this thieving fox will leave its dropping at the excavation. Quite often this thieving fox won't eat the food, but will carry it off a ways and re-bury it. (Can you think of a couple of sets to imitate this?) 

Quite some time ago I used to put bait or lure down in my dirt holes, then give the set a dose of fox urine. Other trappers did the same, and we all caught fox. This will even work today.

But later in the late 1960s, after I had spent considerable time studying the fox and its habits, I used no urine at most of my dirt hole sets that had bait or a food lure at them. Something quit happening at these sets.

We have all seen at times where the fox visited the set, but didn't work it. When I quit using urine at the dirt holes, the fox would work every dirt hole set it visited.

I can only assume that urine at the dirt hole set is relaying the message to the visiting fox that whatever food was in the hole had been taken by another fox. Why should the fox work the set if there is no food there?

Yes, I use urine at some of my dirt holes, but this set where urine is used is constructed just a little different than other dirt holes that contain bait or a food lure. It is at the post sets, flat sets, and others kinds of sets other than the dirt hole is where I will use urine more often. I have about 20 different variations of the dirt hole that I use in conjunction with other sets.

After I had quit using urine at my dirt holes, I had to use "will power" to not reach for the urine container when I would finish each dirt hole. Back then using urine was the thing to do, or so I thought. Sure, fox can be taken at dirt holes containing bait along with a dose of urine, but I will increase my total season's catch by several percentage points by not using urine at my dirt holes containing bait or a food lure. 

I have found it is harder to “unlearn" certain myths and break individual habits than it to learn new ones. I have learned to construct specific dirt hole that contain both food and a dose of urine, and these sets produced consistently. However, this set looks different than the ordinary dirt hole.

Learning to find the answer to a particular trapline problem sometimes will take years. Then when I do find the answer to that problem, it usually leads to at least couple more questions that I don’t have the answer to. This trapping game is a never-ending learning process.

Today, instead of going through the slow learning process that I went through, anyone can shorten this extended learning period by the use of good books or good videos on the subject.