Behavior Glossary

This is a list of behavior terms commonly used on the podcast and in the shelter community.

  • Scientific terms have been simplified for readability. 

  • Definitions in orange are examples of how shelters can define levels of behavior.

  • Definitions in teal are subjective terms commonly used by staff and volunteers. These are examples of how to create an objective definition to prevent miscommunication.


Aggressive behavior/aggression
​​A defensive or offensive bite, scratch, or attack.

Threat displays and other behaviors that allow animal avoid or escape conflict. Can include growling, tooth displays, snapping (no contact), and other behaviors seen as "aggressive" by the average person.

Behaviors and body language indicating motivation for social interaction. Includes solicitation of play or petting. What the average person defines as "friendly."

Anticipation of an aversive event or threat that would require a fight/flight response. 


Pacifying behaviors to avoid conflict with a person or another dog. Often associated with “friendly” greetings. Includes lowered body posture (or groveling), ears back, squinting eyes, “submissive” grin, wiggly approach, “submissive/excitement” urination.  

A level of emotion. Emotions can be negative (ex: frustration) or positive (ex: enjoyment).  ​​​​​​

High arousal/hyperarousal: A state of high emotion (usually negative emotion or conflicted emotions) that causes intense physiological changes and behaviors and may increase risk to the safety of others and the dog’s quality of life. 


anything an animal would avoid or escape, if given the option. 

Distance-increasing behavior to avoid an activity, interaction, or stimuli that increases the animal's stress. Includes averting eyes, hiding, maintaining distance when approached. 

Observable and measurable action when individual reacts to or interacts with their immediate environment. Behavior may be voluntary or involuntary.  

Behavior concern/challenge
Any behavior motivated by anxiety, fear, frustration, or any other form of stress. Any behavior that causes owner/adopter to surrender/return animal or is likely to result in return without intervention. 

  • Mild: No safety or QOL concerns. Only requires basic management strategies. Intervention and support can be done by adopters with appropriate resources (handouts, videos, books), no professional support needed. 

  • Moderate/Serious: Safety or QOL may be at risk. Requires more than basic management. Medications may helpful to bring to manageable level more quickly. Will likely require support from behavior professional to change behavior.

  • Severe/Extreme: Safety and/or quality of life concerns. Behavior is unmanageable without medication and/or behavior modification under the guidance of a behavior professional. Animal may be at risk of euthanasia or return/surrender to shelter due to behavior. 

Behavior consideration
An animal’s behavioral needs in a home environment as communicated to potential adopters or foster homes.


Behavior intervention
Training exercises and/or anxiolytic medication to ease behavior management. Exercises may later be part of a long-term behavior modification program.

Basic: Enrichment and management strategies included in staff/volunteer training for that animal’s handling level. 

Behavior modification
Changing behavior through desensitization, counter-conditioning, and reinforcement of alternative behaviors. Long-term process to change animal's response to triggers and increase tolerance before problem behavior is elicited. 

Behavior professional
A trainer, behavior consultant, veterinary behaviorist, or animal behaviorist with certification or degree in animal behavior with experience coaching pet owners in a professional capacity. 

Behavior support
Environmental changes, mental stimulation, and physical exercises customized to an individual dog in an effort to manage behavior by minimizing the stress that leads to problem behavior. 

To strike or seize with teeth or jaws to enter, grip, or wound. Includes any contact to skin, shoes, or clothing.


Body language
non-verbal communication through conscious or unconscious gestures and movements, observable changes in physiology. 


Internal process to ensure two animals are adopted together. Although a common term in sheltering, referring to pets as “bonded” should be avoided. “Pair bonding” refers to animals that mate for life, which is extremely rare in domestic dogs/cats without human intervention.

Normal behaviors that appear out-of-context when a dog is experiencing stress. May be either a self-soothing or avoidance behavior. These include sniffing, inguinal sniffing or grooming, scratching, redirected bites, object play, and more.  


Inaccurate interpretation of a dog's position within a perceived hierarchy with people or other dogs. Also frequently used as a euphemism for aggressive behavior. AVSAB statement on dominance theory. 


How and at what level an animal chooses to interact with humans and other animals of the same or other species. 


FAS score
An animal’s level of “fear, anxiety, and stress” as defined by the Fear Free program for fast identification and tracking. FAS should not be used to describe behavior and communication should  always include an objective description of the behavior/body language observed. 


Short-term response to escape or avoid an aversive event/perceived threat. 


Intense and difficult to interrupt focus on person, animal, object, or activity.

To grip and hold with mouth, using varying degrees of pressure either in hyperarousal or aggression. May or may not cause injury. 


Food or object that the individual animal is highly motivated to obtain or keep. 


Incidental injury
unintentional and minor injury caused by non-aggressive behavior, such as play.  


Short-term interventions through environmental change, enrichment, and avoidance strategies to temporarily prevent behavior. A form of behavior support. 


Inhibited bite using varying degrees of pressure in exploration, play, or in hyperarousal. 

Descriptions of behaviors or incidents that are measurable (described in specific terms such as size, amount, duration, etc.) and quantifiable (counted in numbers) and does not express opinion, feelings, or personal biases.


Example (see Subjective for comparison): "Astro was in play yard. When a Chihuahua walked past the fence, Astro froze briefly then began deep, rapid, and nonstop barking while jumping against fence. When handler attempted to redirect to treats or squeaky toys, Astro began to bite leash and handler's coat sleeve. Handler had to step outside gate and wait several minutes for dog to recover before re-entering yard." 

Aggressive behavior that is not elicited by stress and either causes injury or death or has a significant potential to cause serious injury or death. Behavior is identified by silent attack/lack of threat display, location of bites, and severity of injury. Progression through predatory sequence to grab-bite and beyond.   


Predatory sequence: orient | stalk | chase | grab-bite | kill | consume 
Breed groups were selected for different portions of this sequence, depending on purpose. Examples:


Herding Breeds = orient | stalk | chase (may include grab-bite)

Terriers = orient | stalk | chase | grab-bite | kill


Reactive behavior (reactivity)
Category of behaviors elicited by high levels stress (fear, anxiety, frustration) in the presence of specific stimuli outside the home. Behaviors commonly include lunging (rushing to the end of the leash) or straining in the direction of the trigger and barking that is difficult to interrupt. Does not apply to dogs that instigate fights or attacks. 


Time and conditions necessary for dog to return to “normal” behavior following an incident that triggered fear, reactivity, or aggression. 


Redirect (attention)
Refocus animal’s attention to another object or activity. 


Redirected bite
When a dog bites their leash, handler, or a companion dog during an episode of reactivity at another person, animal, or object.  


Relaxed behavior
Absence of stress signs paired with signs of affiliation or rest 


Resource guarding
"The use of avoidance, threatening, or aggressive behaviors by [an animal] to retain control of food or non-food items in the presence of a person or other animal” 


Separation anxiety
Category of separation-related behaviors elicited by stress only when and every time when left alone or a specific person leaves.  


The chance or probability that a person or animal will be harmed, experience an adverse health effect, or suffer loss of quality of life due to known factors. 


Animals that display initial reluctance to approach or avoidant behaviors to new people without barking or other threat displays, but quickly and consistently show affiliative behavior ("warm up"). 


Any emotion or sensation that causes animal to avoid or escape environment or situation that tr
iggers fear, anxiety, frustration, discomfort, or pain. 

Descriptions of behavior based on personal opinion or interpretation. Common: Fine, friendly, sweet, aggressive, hyper, excited, etc.  

Example (see Objective for comparison): "Astro is very sweet, but he doesn't like small dogs. He got really aggressive with a Chihuahua. He went crazy at the fence and then got really mouthy. He is not food-motivated. I thought he was going to bite me, so I left the yard. He was fine after he had some time to decompress. He was probably bullied by a small dog in his last home."

Threat display
Distance-increasing signals like barking, growling, hissing, swatting, tooth displays, snapping (no contact), inhibited bite (no injury). 

Animal does not resist or exhibit aggression during invasive handling or other interaction but, unless otherwise indicated, does not exhibit relaxed or affiliative behavior. 


Stimulus that elicits a behavior. Can be sight, sound, smell, and actions of a dog or person. Some behaviors may require a combination of stimuli before eliciting behavior (technical: antecedent). 


Lack of early exposure during sensitive developmental stage (before 14-16 weeks) as suspected cause of fearful, reactive, or aggressive behaviors.