Applying Science to the Art of Detection Canines: Surface Area and Concealment of Targets

By Battelle Staff Members: K. Good, N. Knebel, S. Lawhon, L. Siers, D. Winkel for Working Dog Magazine

When establishing training scenarios, it is common to vary the amount (i.e., mass) of target used. One session may involve several ounces of the target material, while the next session involves several pounds. Although this is good practice, it has resulted in narrowed thinking: Many canine trainers and handlers think solely about target mass when attempting to vary odor intensity. In reality, surface area and concealment of the target are much more important factors.

During olfaction, canines are detecting the gaseous molecules and/or microscopic particles that are released from the surface of the target. If environmental factors (e.g., room temperature) are held constant, the larger the surface area of a given substance, the greater the number of molecules/particles being released. Consider, for example, a drinking glass filled with water. Evaporation occurs only from the surface of water exposed to air. When sitting on your kitchen counter, that glass of water will take weeks to evaporate. If that same glass is spilled onto your kitchen floor, however, the surface area of the resulting puddle is many times that of the water in the glass. As a result, that same amount of water evaporates overnight. In the context of explosives detection work, one pound of black powder in an open bottle has significantly less odor than that same mass of powder distributed across several scent bags.

Furthermore, for detection to occur, those molecules or particles released from the surface of the target need to be physically transported to an area the dog will sniff. The distance and degree of obstruction of the path to the dog’s nose will have a marked impact on odor intensity. As these factors increase (e.g., deeper hides and/or forms of additional containment), odor intensity is reduced. This reduction occurs because the molecules/particles are diluted by the (larger) encompassing volume of air, and some are even “lost” due to chemical or physical interactions with surrounding surfaces.

Understanding the role of surface area and concealment is valuable, as it allows handlers and trainers to better manipulate standard targets and common training exercises to expose their canines to a greater range of target odor intensities, ultimately better preparing the team for the infinite number of scenarios they may encounter operationally.

Read the full content on

Applying Science to the Art of Detection Canines: Blind Searches

By Battelle Staff Members K. Good, N. Knebel, S. Lawhon, L. Siers and D. Winkel for Working Dog Magazine

When training, do you slow down your search when you know a target is present? Do you present the area containing your target more thoroughly? Do you change the grip on your leash as you approach the target location? You may be answering “No,” but your canine partner may answer differently…

Handlers must realize that the elimination of subtle, unintentional cues is nearly impossible when target hide location is known. These cues are problematic because dogs, and animals in general (do an internet search for “Clever Hans” sometime), are excellent at recognizing patterns and cues, which quickly become part of their conditioned response. Since these cues will be absent during actual operational searches (where target placement is not known), it can lead to confusion, nervousness, missed targets, and an increase in false identifications.

To avoid such issues, it is essential that training exercises frequently be conducted “blind” – the condition in which the handler has no knowledge of target placement.

To incorporate blind exercises into your routine, develop a buddy training system, and take turns in the lead role. As the lead, you will be responsible for establishing an exercise that includes some combination of targets, controls, and distractors – the number and location should be unknown to your partnering colleague(s).
In some cases, the training area should be void of targets to ensure that there is no expectation of finding something. While establishing the scenario does require more effort/time for the lead person, the partnering handler(s) can simply arrive and conduct the training. Thus, the overall efficiency of training for the group as a whole is greatly improved.
The lead person should accompany each team during the search and provide assistance when necessary (e.g., prevent the “blind” handler from inadvertently removing the dog from target odor). At the end of the blind searches, the lead person is still able to use the established scenario for critical training; he will be conducting it as a “known” problem, but such situations are ideal for correcting previously identified issues or deficiencies.
Blind searches are one of the most powerful and impactful tools available to detection canine programs. Only under such conditions can trainers/handlers fully eliminate cues, understand true level of competency, and make improvements to real-world detection capability.
For more stories like this one visit

Applying Science to the Art of Detection Canines

Minimizing Contamination & Extraneous Odors


By Battelle Staff Members K. Good, N. Knebel,  S. Lawhorn, L Siers, D. Winkel  | Working Dog Magazine

Use of improper or lackadaisical techniques when handling items in a training exercise can have disastrous effects on your canine’s real-world performance. If your targets are tainted with a different target odor, a distinct nontarget odor (e.g., that sandwich you had for lunch), or a unique human odor, your canine can be inadvertently conditioned to respond to that contaminating odor instead of the actual target odor. As a result, they may perform superbly in your training only to miss actual threats in real searches. Fortunately, the problems associated with contamination and extraneous odors can be minimized when personnel are mindful of the issue and employ appropriate practices. The key is to always think critically about your handling, set-up, and storage protocols.

The strict use of disposable gloves, such as polyethylene food service gloves, is essential for reducing contamination. Wear clean, new gloves every time you handle a target; even one occasion of mishandling can ruin an aid. Don gloves and use them quickly. If you put on new gloves but then get distracted (e.g., answer your phone or make a note in your log book), replace those gloves before touching the target. When done handling the target, immediately discard that pair of gloves. Also, think critically about the handling of unused gloves. Store them in a suitable container; never co-locate them with targets or distracters; and do not transport them in your pocket, because they too are subject to being contaminated.

As another precaution, keep target and non-target (e.g., distracter) materials isolated from one another when establishing training exercises. Separate work areas/stations should exist for these two general categories of training articles. Furthermore, if you are going to use multiple targets in the same exercise, take measures to ensure that the designated target work area does not contribute to cross-contamination. Do not open two containers of different targets next to each other. Also, if you will use a surface in the preparation of targets, cover it with clean barrier paper before target preparation and replace the paper before preparing a new target.

Incorporating these suggestions and others that you identify on your own into your routine training will ensure your canine maintains the real-world, real-threat detection capability you require to be successful.