[Annual Rodent Control Issue] Snap Trap 101

I was at a gun show and flea market up in Hillsville, Va., several years ago when I spied an old rat snap trap. I tried to hide my enthusiasm as I casually looked at the old pegged wooden trap. I knew that this wasn’t just any old rat trap but the exact same trap from the late 1800s that was pictured in the book The Ratcatcher’s Child by Dr. Robert Snetsinger. After a brief discussion with the vendor, and probably paying too much for it, I was able to take “the find” home to add to my rodent trap collection.

I grew up trapping just about every kind of critter that I could get after, and an interest in snap traps and using snap traps to capture rodents has kind of come naturally to me. With electronic technology that now allows us to remotely monitor rodent activity; tamper-resistant rodent bait stations in every style, shape and color; glueboards in multiple sizes, with and without attractive odors; plus a plethora of multiple-catch rodent trapping devices now available, many folks in our industry often may overlook the efficiency and usefulness that rodent snap traps can achieve as part of a rodent control and prevention program. In this article we’ll take a closer look at the varied use of rodent snap traps and how getting back to the basics of “Snap Trap 101” can benefit your business.

RODENT PROGRAM NEEDS. It should go without saying that the beginning of any rodent control and prevention program should include an extremely thorough inspection and site evaluation. Factors such as sanitation, structural integrity, business type, current level(s) of pest infestation, potential for infestation, adjacent structures and exterior landscaping all should be considered prior to rodent control or preventive programming implementation. When it comes to rodents, I always will remember hearing industry consultant Bobby Corrigan saying “it’s not so important how many rodents that we capture or ‘harvest’ at a location, but how many are still present.”

When going into a new or existing account with a rodent problem we need to be able to establish a program that will provide effective and efficient results. We need to also keep in mind the vast differences in the habits of rats vs. mice and even the differences in the various species of rodents that you may be dealing with. I believe I also heard Bobby make the statement that mice can be classified as “curious investigators” and rats as “cautious avoiders.” Always keep in mind that these are two different types of critters with only some common habits.

One example of “species-specific rodent behavior” that we often encounter at our firm is when folks call during the fall thinking they have squirrels in the attic. Sometimes there are, in fact, squirrels present, but it’s also very common to find a healthy population of deer mice living exclusively in the attic space. These mice rarely enter into the living areas of occupied homes but their presence in the attic spaces does present a situation that dictates control program implementation.

SNAP TRAP SELECTION. In many situations there is a need for rodent carcass containment to prevent product contamination or a need to minimize the potential for a dead rodent odor. There also may be a need to obtain rapid control of an existing rodent infestation involving a large number of animals. When either of these situations occurs we have a number of tools or control devices that we can use in combination to maximize our odds for success. In many situations, snap traps are one of those tools that we should regularly consider.

I don’t have a complete working knowledge of every make, model and design of rodent snap traps that are now available. I do, however, know what has worked for our firm. I personally prefer a snap trap with an extended pan vs. the older style “treadle type” pan. Traps with an extended pan can be baited with a wide variety of attractants, set perpendicular to walls to capture rodents as they naturally move along the edges of walls, or even attached, baited or unbaited, to overhead lines or pipes where rodents are traveling overhead. The added pan surface also creates a natural platform for a rodent to step up on to investigate the bait material.

We use a lot of the expanded trigger Victor snap traps on a regular basis, and these traps have the bails temporarily attached to the main body of the trap with a U-shaped staple for ease in packaging and shipping. I always instruct our technicians to use a flat screwdriver or car key and insert this directly under the bail next to the staple and pry off the staple.

If technicians routinely pull the bails to loosen them from the temporary staple this will often bend the bail. Any of the bail-and-pan or bail-and-trigger snap traps should be checked for needed adjustments prior to setting. I have not found this to be the case in most of the molded plastic type snap traps.

When it comes to bait selection I like to consider what resources are available to the rodents that are present as well as what they are currently feeding upon. It may be possible to limit rodent access to their preferred food and use a small amount of that food as bait on the traps. It also may be possible to make multiple trap placements closer to nesting/harborage areas that are more readily accessible to the rodents than existing food sources. Some common baits include peanut butter, nut pieces, chocolate, cat food and even the new non-food attractive paste baits. Often overlooked are potential nesting materials such as cotton, yarn or even pieces of string tied to the pans of snap traps. I often will set a number of snap traps unbaited along wall edges perpendicular to the walls during an initial account startup.

Always keep in mind that it’s a lot better to go in with way more snap traps than you think you may need and saturate the area(s) of concern. Check these traps at least daily and add and/or relocate traps as dictated by the results of your efforts. Also make sure to number and map out trap locations or at least count the number of traps set to ensure recovery.

In the past, I have gone into grocery store accounts after hours and set snap traps up on and under the stock shelving of the gondolas. Failure to recover these traps prior to store opening the next morning could result in some extremely negative public relations!

In order to better illustrate the applicability for the use of snap traps in today’s marketplace the following are some snap trap case studies for your review.

The $250,000 Rat. A number of years ago we were scheduled to start service for a brand new client that manufactured glass containers. The week before we were scheduled to start service we received an urgent call from an extremely anxious plant manager. The conversation was basically, “We need ya’ll in to start today! We had a pallet of containers inspected and they found rat droppings on the pallet. Our warehouse is shut down until we catch this thing and it’s costing us $125,000 a day!” Within the next hour I arrived on site with our service manager to assess the situation. The warehouse was approximately 200,000 square feet and literally packed full of pallets with new glass containers. After an extensive inspection we found no evidence of rodent infestation other than the fresh rat droppings that had been collected from the pallet in question. After reviewing the results of our initial inspection we felt that it was possible that there could be only one rat that was present.

After some extensive brainstorming we determined that placement of snap traps would be the best rapid solution to capture the rat; however due to the size of the warehouse, effectively saturating the entire building with trapping devices was not practical. No food sources were available to a rat in the warehouse, so we came up with the plan to place 120 numbered paper french fry containers in a grid pattern with a small amount of peanut butter and canned cat food in each container. We would inspect these containers every hour until we noted any evidence and then saturate that specific “zone” of the warehouse with snap traps once any sign of activity was detected. Fortunately we detected feeding on peanut butter on either the third or fourth round of inspections. We then went in with approximately 100 rat snap traps baited with peanut butter in this specific area and continued monitoring. On the second hour of inspection we captured one large adult Norway rat and, even though we continued to monitor through the next day, had no other signs of activity. The warehouse was reopened the following morning and we had one very satisfied client!

THE CHOCOLATE-LOVING SUPER RAT. One day one of our technicians came into my office saying that he had a “chocolate-loving super rat” that he couldn’t catch or kill and he needed help. Apparently the technician had a Laundromat that had an attendant and a candy counter for their customers. The customer said the super rat was literally eating up the profits!

When I got out on site, I observed enough rodent trapping equipment and bait to make the Laundromat look like a mined military area. Upon closer inspection it appeared that the rat had a real love affair for Hershey’s chocolate and he had just about eaten or carried off most of the store owner’s stock. In an adjacent furnace room, by holding my flashlight at an angle parallel with the floor, I was also able to observe multiple sets of rodent tracks in the dust. The tracks went around the rodent bait stations and baited snap traps. (Remember “cautious avoiders” and the term neophobia — having an aversion to any new objects in an area.) Apparently the rat was traveling back and forth through this area on a regular basis to a nesting site somewhere behind or in the furnace equipment.

I went back out to my truck and took out two extended-pan snap traps. I then set them in the furnace room with the trap pans extending across the rat’s natural travel path at two different locations. I then got a broom and dust pan and swept up a big pan full of dusty floor debris which I then sifted over the traps to blend them in completely with the surroundings. To finish off these two sets I moved a couple of boxes to slightly restrict the rat’s natural movement when traveling through this area. The next morning we found that the reign of the “chocolate-loving super rat” had been ended.

RATS IN THE AIR DUCTS. One afternoon a panicked homeowner called our office saying that rats apparently had gotten into her crawlspace and were in her air conditioning duct work trying to come through the floor registers.

Due to the concern for carcass containment, I instructed Steve, one of our technicians, to take out a quantity of Trapper T-Rex rat snap traps and some 14-gauge wire. I then told him to tie a section of wire to the end of each trap and remove each floor register. He would then lower the baited traps down into each duct opening and tie the wire to the register grating prior to placing them back. Before Steve had completed placing all his traps he heard a trap go off, and he had trapped his first rat. Four more rats and a repaired crawlspace door later, the HVAC folks came and repaired the damaged flexi-duct work and we had a very happy new customer.

A MOUSE IN THE DINING HALL. One Friday afternoon the call came in from a local university that they had a mouse jump out of a box that had been brought into the dining hall the previous day, and the mouse had been running back and forth through the dining hall during lunch the past two days. The university had received several complaints from students about the mouse and they informed the food service vendor and the current pest service provider that our firm was “taking over the situation” and going to come in and solve the problem. (Nothing like the pressure of extremely high performance expectations to get you sweating!)

My partner, Frank Fowler, and I went out that afternoon and surveyed the situation. During our inspection we did find several areas where a few mouse droppings were present. Frank and I were back on site that evening after the dining facility closed and placed out approximately 75 baited mouse snap traps. Early the next morning (Saturday) Frank gave up going deer hunting for going mouse hunting. Fortunately his trip was not wasted and the culprit was captured in one of the traps. As Frank clearly pointed out, not in one that I had set, but specifically one that he had set!

WHERE ARE THE MICE COMING FROM? I once had a confectionery product distribution warehouse where we maintained an extremely extensive weekly rodent prevention program. The only weakness in their programming was that they were in a larger building that had non-food tenants on either side. Along the rear wall of the facility we started routinely capturing mice in our multiple-catch trapping devices and the warehouse manager was very concerned about where these mice were coming from.

After reviewing the service logs and inspecting the interior of the warehouse and the exterior perimeter of the entire building complex I told him I felt the only explanation I could provide was the mice were coming in through the building weep holes and then up and over the concrete block walls or coming up and over from the adjacent occupied spaces. To put it mildly, the client was very skeptical of my evaluation!

I finally convinced him to lift me up to the back wall using a fork-lift cage where I then set about a dozen snap traps along the top of the hollow block wall. I also secured them in place using liquid nail adhesive so that they wouldn’t fall down into the wall cavity if they were tripped. (Note that Hercules Putty would have been a good alternate choice for securing these traps.)

Two days later I had captured three mice on top of the block wall. We then blocked mouse access through the weep holes around the entire exterior of the building using small amounts of Stuf-Fit copper exclusion material, expanded their exterior rodent baiting program to include the entire building, and never had a reoccurrence of repeated interior mouse capture. (Note that mice can climb a concrete block wall like squirrels going up a tree.)

CONCLUSION. Today it is truly amazing to see the wide variety of control and preventive tools that the pest management industry has available to address rodent concerns. As pest professionals we should always have an extremely thorough working knowledge of the biology and habits of the animals that we are targeting, as well as the options available for control and prevention.

When addressing rodent concerns I hope that the information contained within this article and illustrated through these case studies will positively influence your decision in seeing that getting back to the basics of “Snap Trap 101” can often be a valuable tool to help us solve and prevent rodent concerns.

The author is owner of McNeely Pest Control, Winston-Salem, N.C., and a member of the Copesan Services Technical Committee.

Trapping Tips

“Commensal Rodent Facts” from Liphatech provides an overview of rodent IPM, as well as descriptions of the house mouse, Norway rat and roof rat. It also focuses on the topic of trapping, offering a number of practical tips for pest management service technicians. This section is reproduced here with the permission of Liphatech.

In sensitive areas where rodenticide use is not permitted, traps are especially useful. Traps also prevent rodent deaths in inaccessible areas. After rodents and their patterns have been identified, follow the appropriate trapping methods, including the following recommendations:

• Store traps away from insecticides and chemicals that may impart a flavor. Remember, rodents have a keen sense of taste.
• Bait snap traps with food that is more attractive than other readily available food sources, such as gum drops, peanut butter, bacon, nutmeats or dried fruits (raisins). Secure bait to the snap trap trigger — a length of thread works well. For rats, fish (tuna) and meat (cat/dog food) may be used to bait traps. Glueboards can be baited with non-oily foods. The use of peanut butter, bacon and other oily, greasy foods will cause the glue to lose its stickiness.
• Bait some mouse snap traps with nesting materials, such as cotton or dental floss, and a drop of vanilla. Mice constantly look for nesting material.
• Place mechanical or snap traps and glueboards in areas unsuitable for rodenticide applications.
• Position snap traps and glue boards to intercept rodents in runways. Place snap traps with the trigger toward the runway — generally along a wall, in corners, behind and under objects, and near abundant tracks and droppings. Snap traps also may be attached to pipes and beams used as runways.
• More traps are better than fewer traps.
• Pre-bait traps until rodents, especially rats, overcome their fear and take bait readily. This may take several days for mature rats.
• Glueboards shouldn’t be used in areas with excessive dust or wetness — both elements make glueboards ineffective.
• Check boards frequently to prevent rodents from escaping.
• For mice, repeating or automatic mechanical traps may be used. Watch for tracks in the dust on the top of low-profile traps.

The brochure is available by contacting your Liphatech sales representative or at www.liphatech.com.