Convergence: The Hidden Hide

Author: Judith Guthrie

Convergence happens when odor molecules from two or more sources intermingle in part or in whole. Odor interaction changes the search picture by asking the dog to separate one source from another while working through odor from both.

A hide can become harder to source when its plume edge sits inside odor from another hide. The dog may recognize target odor and work with purpose, yet still need more education to identify which source each piece of odor belongs to.

The distinction changes how teams read advanced odor puzzles. A dog can have odor obedience, hunt drive, and target odor recognition while still developing the skill set needed for a specific convergence picture.

Plume Edges Shape the Search

Plume edges give the dog information about the shape of the odor picture. They help the dog identify where odor becomes available, where it changes, where it weakens, where it strengthens, and where one source may separate from another.

Some edges present clearly enough for dogs to sort quickly. Other edges sit inside a larger odor picture, especially when multiple hides create overlapping plumes. Hidden edges require a broader odor library, more sourcing fluency, and more experience sorting source from source.

In a line, triangle, or other convergence setup, one hide may sit inside the odor picture created by the surrounding hides. The dog may work odor along the line or through the triangle while still learning how to isolate the source whose edge is less available.

Why the Middle Hide Can Disappear

Picture three hides in a line or triangle: Hide A, Hide B, and Hide C. Hide B sits in the middle or functions as the middle hide in the odor picture. Odor from all three sources can overlap, and the edges of Hide B’s plume can sit inside the plumes from Hide A and Hide C.

Dogs work the odor picture with their nose. As odor strengthens, they work deeper into the picture. As odor weakens, dissipates, or changes, they turn, compare, and work back toward stronger information. That pattern helps explain the snaking, casting, turning, edge bouncing, and larger body movements handlers often see while dogs source.

In a simpler picture, edge changes help the dog work from less odor to more odor and narrow the path toward source. In an advanced convergence picture, the dog may work to the available edge of Hide A or Hide C instead of finding the hidden edge of Hide B. The dog may be working odor correctly while still sorting the wrong edge for the source we want them to isolate.

Middle hides often source later for exactly this reason. Not always. Some dogs sort the problem quickly and drive straight to source. As a common pattern, dogs often solve the more available outside sources first, then return to work the middle source after gaining more information about the larger picture.

To source Hide B cleanly, the dog must learn to separate Hide B’s odor from the surrounding odor and stop treating the outer hides’ edges as the only useful boundaries in the puzzle. Clean sourcing of Hide B takes an extensive odor library, structured exposure, and practice sorting individual sources inside an overlapping odor picture.

The Environment Changes the Picture

The physical hide locations only tell part of the story. The dog works the odor picture the environment makes available in a specific moment.

Pooling can create a strong area of interest away from source. Airflow can push one plume across another source, stretch an edge, change the first point of odor contact, or make one hide more available than another.

Surfaces, barriers, corners, temperature, humidity, and wind can all change how the dog encounters the puzzle. A quick label after a miss gives the handler less useful information.
The useful review question becomes: what odor information did the dog have available, and what part of the sorting problem did the setup ask the dog to solve?

A Simple Review Framework

When you review a convergence puzzle, start by looking for the edges. Watch where the dog first shows odor, where the dog changes direction, where the dog re-enters odor, and where the dog slows, compares, returns, or works more carefully.

Those moments help identify the sorting problem. They may show a dog working through a blended odor picture, a hidden edge, a pooling area, or a source sitting inside the larger plume picture.

Next, study the relationship between hides. One source may offer more available odor, while another source sits inside odor from a stronger or more familiar picture.
A middle hide in a line or triangle may require the dog to separate that source from the larger odor picture before the hide becomes obvious enough to source. Four useful questions can guide the review and give the handler better information before choosing the next training step:

1.   Where did the dog first show odor?
2.   Where did the dog lose clarity or change direction?
3.   Where did the dog re-enter odor, compare, or return?
4.   Could one source be sitting inside the odor picture from another source?

Build the Skill the Dog Needs

Working convergence is a specific skill set. The different types of convergence create subsets of that skill set, and each version asks the dog to solve a slightly different problem.
A dog may need more experience finding hidden edges. Another may need more clarity moving from found odor back into the hunt for unfound odor.

Others may need a source-separation progression before the puzzle gains complexity. Good training starts by identifying the skill inside the problem.

Hide distance, airflow, start point, access, height, and environmental structure can all change what the dog is learning. Repeating the same setup without analysis gives the team less useful information.

Adjusting the setup with a clear purpose gives the dog a better education. The goal is to help the dog build an odor library and learn how to work through overlapping plumes, hidden edges, pooling, and shifting airflow.

The handler’s job is to study the picture well enough to choose the next useful rep. A missed hide becomes useful information when it helps identify the next skill to build.

Use the framework to read the odor picture with more precision. In my Odor Series Part 2: Convergence webinar through Scent Work University, I go deeper into how convergence presents, why dogs may get stuck or quit on these puzzles, how hide distance changes the problem, and how to build the skill set more deliberately.

Listen to the audio version of this blog post here:

Judith Guthrie is a detection dog trainer, handler, and instructor as well as a certified for The National Tactical Police Dog Association (NTPDA) and the International Bed Bug Resource Authority (IBBRA). Additionally, Judith is an approved AKC Scent Work Judge, NACSW Judge and USCSS CSD and Judge.

Raised around working dogs, mainly search and rescue dogs and retired police dogs, Judith has been part of the dog world her entire life. Dog training and canine behavior is a passion of hers. Judith strives to understand the why of a situation and how to mold the behaviors offered in the direction she needs them to go. In training, she enjoys it all from competition obedience and agility to every piece of police dog work and everything in between.

Judith has been involved in the training of detection and patrol dogs for police, government, and private agencies across the United States. She has trained detection canines for narcotics, explosives, bed bugs, and human remains to name a few. On the competition side she has multiple titles in Agility, Obedience, Rally, and K9 Nose Work. She also enjoys finding ways her dogs can help in everyday life from carrying snacks and water when hiking to pulling the feed cart to feed the livestock.

In Nose Work, Judith has competed up to the national level and has partnered with a variety of breeds from mixed breed dogs, to Labradors, Beagles and more. Professionally she handles several bed bug detection, narcotics detection, and explosive detection canines for private businesses and families in the western United States. Judith also loves developing young detection dogs and learns something from every dog.

Judith's business, Nose Dogs Detection Services, is a police and detection dog training facility. Through Nose Dogs, Judith offers trained and prospective police and detection dogs for sale, detection dog handling courses, workshops, certifications, personal protection dogs, companion dogs (trained, untrained, and/or titled), and a list of detection services for private individuals and businesses. When possible she also works with a variety of rescues.

Scent Work University has been incredibly fortunate to host Judith for a number of online courses, webinars and virtual events. Check out her entire library here.