Snap Trap Baiting Strategies

But luring rodents to traps is more difficult than tying a piece of Swiss cheese to the trigger. Although it’s been said that trapping rodents can be more art than science, the fact is, it’s some of both.

ON BAIT SELECTION. There’s a difference between selecting a bait to trap just a rodent or two, and selecting baits for large numbers of traps. For a few rodents, practicality is the rule. Peanut butter, for example, appears to be attractive to rodents, is easy to apply, is convenient to keep fresh, and is handy on the service truck for long periods of time. Some professionals also have good success with candy, caramel corn and various nut meats. Some PCOs have been satisfied using peanut oil lightly brushed on trap triggers.

But what about trap bait selection for rodent initials or jobs requiring many traps? In these situations, it is important to get the best return for your time invested in baiting, setting, and installing the many snap traps needed to ensure your trapping program is both efficient and effective. For example, if you install all traps with only one bait, you risk mis-targeting the preferences (if one exists) of the local rodent population. Or, you can miss those rodents which may not be attracted to the bait you’ve selected.

Although it is true that the domestic rodents tend to be omnivorous and opportunistic in their feeding strategies, many variations exist on this model depending on the local environmental conditions of a particular infestation. A group of rats or mice, for example, may be acclimated in a particular building or area toward the local available food which they have been feeding on. But these same rodents may also be receptive to certain foods or items which are missing in their diets.

For large trapping programs in areas where a clear food preference may not be known, the following strategy sometimes proves helpful. Pre-bait all snap traps using equal portions of the following three or four bait choices: 1) baits that match the suspected predominant food of the local population; 2) a food bait which may supplement nutritionally the suspected local food; 3) nesting materials; and, 4) suspected “natural” foods of the rodents (cockroaches, slugs, snails).

For example, in a large office complex I would initially bait one-third of the traps with snack foods (matching the food of the office mice); one-third with bacon pieces; and one-third with nesting materials. This way, I let the rodents tell me which bait they prefer. If the first inspection indicates a strong preference for one bait, that is the bait to use during the actual trapping program. If all baits seem to be equally taken, then using all the baits is a good strategy.

One of the attractive aspects associated with the use of nesting materials as baits is that rodents forage for nesting materials on a routine basis. Research has shown that pregnant mice spend significant time foraging for nesting materials with the onset of cold weather, as well as just prior to when they birth litters. They diligently forage for nesting goods even when they have a good nest already constructed.

“Natural food” baits are less convenient for large trapping programs than are food or nesting baits. But in cases of elusive roof and Norway rats, natural baits might prove to be the right tool. (See “Vertebrate Pests,” November 1996.)

“PRE-CONDITION” THE TRAPS. In addition to using a few different baits, another baiting strategy to expedite trap success is to “pre-bait” or “pre-condition” your snap traps. This is done by placing small amounts of the target bait for that trap on the sides or trap edges adjacent to the trigger, and/or at the ends of the unset traps. This may help to acclimate cautious rodents to feed from the traps more readily. This does add an extra service visit prior to the actual trapping program, but in the long run, spending a few days pre-conditioning your traps can help reduce callbacks.

One of the basic “golden rules” for trapping rodents is to make the program as quick and decisive as possible. Spending time up-front offering the rodents a choice of baits in addition to pre-baiting your traps can help you maximize your bait selection, and also can pre-condition the rodents to more readily interact with the traps.

Still, research is needed to scientifically address some of the foraging strategies of the domestic rodents inside buildings. However, I don’t expect any single “magic bullet” bait emerging that will be universal for all the various trapping scenarios. It would be difficult, if not impossible, to design research which would provide one explanation for feeding and foraging behaviors which are also influenced by thousands of different environments.

This reinforces the importance of conducting multiple-baiting and pre-conditioning efforts within your infestations to get the best “data” to guide you toward cost-effective trapping programs.

Dr. Robert Corrigan is president of RMC Pest Management Consulting, 5114 Turner Road, Richmond IN 47374, 317/939-2829.