[BED BUG SUPPLEMENT] Buddy on the Spot

Features - Bed Bugs

With the proper training — for both animals and humans — bed bug scent detecting canines can be your best friend when it comes to finding infestations.

March 31, 2011
Kelly Mannes

Seeing is believing when it comes to pests — most of the time. Infestations are often discovered by property owners who learn they have a problem only because they’ve seen or heard it themselves. Pest management professionals, too, rely heavily on their own faculties to know if pests are on site.

And while trained professionals can generally find evidence of pest problems much sooner than their customers, some of the most damaging pests live out of sight and are too small to be detected until their numbers have swelled.

To detect these pests early in the game, a pest management professional may have to perform costly procedures such as tearing out walls or pulling up floors. Even then, if the pest population is low, there’s still a chance that the problem will escape detection.

So, at a time when property owners are increasingly dependent upon PMPs’ abilities to identify such threats, the pest management industry needs a way to ensure accurate, early detection while avoiding unwanted costs and unhappy customers.

One solution to the dilemma may be bringing in the reinforcements. That’s the assertion of extension specialist Dr. Faith Oi of the University of Florida Department of Entomology and Nematology. Oi contends one of the most promising pest locators comes in the form of canine pest detection.

A leader of the Florida School IPM program and an advisor to the National Entomological Scent Detection Canine Association, Oi has also evaluated numerous technologies currently in development or already in use within the pest management industry. Having started her work with canine insect detectors more than 12 years ago, Oi now considers these dogs part of the future of pest management.

During her recent appearance at the National Pest Management Association’s 2010 PestWorld conference in Honolulu, Hawaii, Oi spoke about the efficacy of canine pest detection, outlined the most common legal issues the industry could face, and explained how, in the right hands and with the right training, a canine detector can be a PMP’s best friend.

Before deciding whether a canine detector is right for your pest management company, it’s important to understand what, exactly, these dogs do. According to Oi, canines have a few thousand times more olfactory receptor cells than humans, which means they have a sense of smell “from 10,000 to 100,000 times better…than humans.” With proper training, canine detectors can learn to identify a certain scent and alert their handlers to its presence. Basically, said Oi, “Canines are insect scent detectors.”

Canines have been used to search out anything from non-biological weapon accelerants to human remains. In the pest management industry, it’s far more likely that you’ll want to use a canine detector to find those insects that, in their early stages, can escape human detection. “If the termites swarm, you probably don’t need a dog to tell you they’re there,” said Oi.

Similarly, slower, larger insects that are easier to spot, and insects that leave evidence of their presence, also usually won’t require a canine’s special abilities. “Canines are effective when items of interest are hidden or in low numbers,” explained Oi. They are especially useful, she said, for cryptobiotic insects. Some of the most common examples include bed bugs, gypsy moths, red palm weavers, screw worms and termites.

When it comes to detecting gypsy moths with canines, however, the timing makes all the difference. “You don’t need a dog to tell you once infestation has already occurred,” said Oi. Skeletonized leaves, bark crevices, defoliated trees and leaf litter are all telltale signs of a gypsy moth infestation.

Being able to find the moths before the damage is done is what makes the canine detector valuable. “If you can destroy the egg cases, you can control the moths,” says Oi. And a trained canine detector can track the egg scent to its point source far more quickly and effectively than a human inspector relying on visual clues.

It’s important to make sure that your dogs are trained to meet certain performance objectives. One documented method of training is the U.S. Customs Method with a modified food reward. It is also essential that canines receive both search and detection training. “Search patterns in different locations require different skill sets,” Oi said. Dogs must learn how to search both on- and off-leash in multiple settings.

Detection, on the other hand, is the dog’s ability to alert to the presence of a particular substance. Canines can also learn “discrimination,” which is the ability to distinguish between similar substances. For example, instead of alerting for termites, the dog could alert for a single type of termite. As Oi stated, however, “if there is an infestation of a pest, it usually doesn’t matter what pest for you to have to take care of it.”

During training, the scent used should be a pure sample from a live target insect. Oi found that many dogs initially alerted to samples containing dead target insects, but within a few repetitions and with proper correction, the dogs learned to differentiate between live and dead scents. “[You] can get a dog trained to any scent in two to six weeks,” said Oi. The problem is, “once a dog cues in on a scent, it’s hard to retrain.”

The trainer must also vary the tests so that the dogs “hit on” the correct scent case (often a PVC pipe) through their own detection abilities, and not because of habituation.

When termite dogs were trained for Oi’s research, a modified U.S. Customs Method with food reward was used. In brief, basic training can be broken down into two main phases: First is the basic retrieve. In this case the trainer plays with the dog using a towel, which the dog then relates to as a toy. Once the dog learns to retrieve the towel, a sample of the desired insect scent is wrapped in it so that the entire process becomes associated with the scent.

The second training segment is the buried-hide phase. Once the dog has mastered basic retrieval, the trainer buries a sample of the target item. In the example of termites, termites may be hidden for the dog to find. The dog already recognizes the scent from the basic retrieval process and associates it with a desired toy. This toy association reinforces the search pattern. When the dog indicates correctly that it has found the target item, it is given a food reward.

If your pest management company decides to invest in a canine detector, it’s equally important to find and train a capable handler. “The dog is a sensor, and the handler is the interpreter,” explained Oi, adding, “almost all erroneous alerts are handler errors [from] misinterpreting the canine’s signals.”

Such mistakes can be avoided, however, with proper training and experience. “[Handlers] need to know when a dog is simply scratching in order to bring the scent up to the surface so that it can better read it, or if it’s a real indication,” said Oi. For each canine, these signs may vary slightly, so it is important to have a handler who is familiar with the particular canine on duty. In the case of narcotics, said Oi, “it’s usually about two years before a handler is really comfortable reading the cues of the dog.”

The biggest handler problem, says Oi, besides misinterpreting the canine’s signals, is giving hints or cues during training. A cue, for example, may consist of pointing to the location of the hidden target item during a bury-hide session. To avoid this problem, she recommends the “blind-hide” method of training in which the handler also does not know where the target is hidden.

Once the canine is trained to alert its handler, there are four possible outcomes that may arise during a session — with two being correct and two incorrect. Target positive occurs when the canine correctly alerts, or indicates, the presence of the target, and target negative occurs when the canine does not alert its handler when the target isn’t there. Meanwhile, a false positive arises if the canine alerts when the target is not present. And in false negative, the canine fails to alert, yet the target is present.

Canine detectors are not perfect, and there is always the risk of a false positive or false negative outcome, which could prove costly. Legal concerns can be mitigated with proper documention, including training records. “The bottom line is,” said Oi, “people call in pest control because they think they have a problem.”

Regardless of their training, like any other employee, the effectiveness of a canine scent detector is subject to working conditions. For example, one of the biggest problems for canine detectors is hoarders, says Oi. The hoarder situation, she explained, “does impact some of the ability of the dog because the dogs have to be close to the scent of the live insects.” This is particularly difficult with bed bugs because of their size, agility and love of hiding places.

When it comes to termites, there is a common expression in the pest management industry: “It’s not if but when you’re going to get sued.” The same problem is starting to appear with bed bugs, especially from increased litigation due to incomplete eradication in treatment areas.

Fortunately, the canine narcotic detectors have already set a precedent for canine detection in law. “Courts have already deemed that canine indications are reliable enough to serve for probable cause,” said Oi. She explained that courts have determined a canine’s sense of smell to be sui generis — in a class of its own. Because of the specificity of the procedure, judges also are increasingly requiring proof of specific canine reliability. Cases on the narcotics side have been lost because judges have questioned a dog’s reliability based on poor training, inconsistent records, searches in conditions without reliability controls and handler cuing.

“On the pest control side, we don’t want to be on the losing side of a termite or bed bug case because we lack evidence of the reliability of the dog,” said Oi. That’s why documentation and records are essential. In these records, courts are typically looking for a number of things: evidence of the training the dog has received, the criteria for selecting the specific dog(s) used, the standards the dogs were required to meet to complete training, and the track record of the dog up until the search, including false indications.

Point source dogs follow a scent to the point of highest concentration until they reach the source of the odor. Narcotics dogs also use a point-source method of detection and training procedure similar to the one used for structural pest management, but the amount of time spent in training, recertification requirements and functional situation training varies between the two industries.

Currently the NPMA’s Insect Canine Detection Committee is working to set a uniform performance standard for its members to help ensure quality training and maintenance of canine detectors. However, said Oi, the industry is still considering how to categorize the effectiveness of these dogs, and they don’t want to mislead consumers about expectations.

Until these industry standards are set, if your pest management company does decide to invest in a canine pest detection unit, it’s essential that you keep thorough documentation of your company’s training method and recertification process, as well as records of each dog’s training and recertification results and field performance. It’s not as important how the dogs were trained, it’s how well they meet performance objectives, Oi said.

With the proper training, maintenance and handler, a canine can be up to 98 percent effective in the field and detect as few as one of its target insects. Though there is a risk of false alerts, canines trained and documented according to stringent standards will receive many legal safeguards as set by precedents from canine narcotic units.

Overall, canine pest detection has opened up new possibilities for fast, effective and proactive insect detection within the pest management industry, and it looks like these dogs are here to stay.

The author is a freelance writer based in Washington, D.C., and can be reached at