The Beagle Brigade

What You Need

The Beagle Brigade U.S. Customs & Border Protection


To help students develop an understanding of animal behaviors and the interaction of innate abilities and learned behaviors.


In this lesson, students will develop their understanding of animal behaviors and the interaction of innate abilities and learned behaviors. The Beagle Brigade is a team of beagles and their human handlers who inspect luggage at U.S. airports searching for agricultural products. They are part of the United States Department of Agriculture's Animal and Plant Health Inspection Service (USDA-APHIS). The USDA is charged with making sure that meat, animal byproducts, fruit, and vegetables that can carry diseases and pests harmful to U.S. agriculture are kept out of the country. Often these products are brought into the country by travelers. The APHIS works in conjunction with the U.S. Customs Service, Public Health Service, and Immigration and Naturalization Service at entry points to the U.S., including land borders, ports, and airports to make sure that this doesn’t happen. The Beagle Brigade contributes to this effort by working in the baggage-claim areas at international airports. Dogs in the Beagle Brigade wear green jackets. One reason why beagles were chosen for this work is that they are small and easy to care for. They also are not as intimidating to people who are uncomfortable around dogs—such as larger dogs like German Shepherds. This is important in busy international airports where there are large numbers of people at all times.

Although beagles, known to be willful, are not generally considered good working dogs, they are well suited to this task because of their superb sense of smell. What makes a beagle's sense of smell so good? Humans have an estimated five million scent receptors (cells used for smelling) concentrated in a relatively small area at the back of the nose. By comparison, beagles have an estimated 220 million scent receptors. Not only do beagles have an uncanny ability to detect scents, but after extensive training, they also are able to distinguish one odor from another and remember it. Because of this, they can be taught to distinguish between the scent of a "restricted" item (such as a fruit, vegetable, or meat) and a non-restricted item. When a member of the Beagle Brigade smells a restricted scent, it sits down next to the luggage to alert its handler, who then talks to the owner, and, if necessary, performs a search. Experienced beagles have a 90% success rate and can recognize almost 50 distinct smells.

Planning Ahead

The article Dog Intelligence can provide you with background knowledge about how dogs generally learn.


Begin by talking about dogs, specifically working dogs. Ask students to describe situations in which they have seen working dogs. Ask students if they can name breeds of dogs that they think are more suitable as working dogs, and to speculate about why they think these breeds are well suited to the work they do. Ask any students who have dogs to describe what types of tasks they think their dogs might be able to accomplish.


Next, refer students to the Beagle Brigade student esheet and instruct them to follow the directions in the section called “Going Online.” This will lead them to a PDF called USDA's Detector Dogs: Protecting American Agriculture.

After students have finished the first part of the esheet, discuss the article with the class, asking questions such as:

  • What parts of the dog’s body systems help it to be able to detect specific restricted items? (The beagle’s nose has an estimated 220 million scent receptors. The part of a dog's brain that receives messages from the nerves of the nose is also highly developed and can store scent information the way a computer does.)
  • Why is a beagle a natural choice for the job of detecting contraband food items at airports? (The beagle’s curiosity, intelligence, high response to food, and superior sense of smell make it suitable. Its relatively small size and good health also make it easy to handle and care for.)
  • How are some of the special needs of Beagle Brigade dogs met? (Answers might include that they are fed a high protein diet and rest for at least 20 minutes of each work hour. Students may also mention that they live in kennels and not in homes because of their heightened sensitivity to food smells. The dogs also are closely monitored for their continued interest in their “work” and are retired to private homes if they demonstrate disinterest.)


Using the esheet, students will be directed to three additional brief news articles about the Beagle Brigade. They will be asked to use what they have learned in the lesson and from these stories to write a fictional account about an encounter with a Beagle Brigade team at the airport. They can be as creative as they like, but their stories should include a description of how the beagle is able to detect illegal food products in passenger luggage.


The Science NetLinks lesson, Pet’s: Oh Behave, can be used before or after this lesson to help build student understanding of the ideas in this benchmark.

The following resources include more information about the how dogs’ sense of smell can be used to “sniff” out a variety of problems.

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Lesson Details

Grades Themes Project 2061 Benchmarks National Science Standards