On a fairly regular basis, my chocolate-brown chihuahua mix will get territorial about some limbless, chewed-up toy that no one else wants. She’ll prowl around with the toy in her mouth, hackles raised, while growling to warn that the headless elf from last Christmas is all hers. 

The rest of us will ignore her, and eventually, she’ll relax. Or she’ll cool it when I inform her that she can’t come up on the couch until she stops.

My little dog isn’t the only one who has territorial behavior. Many animals display a behavior called “resource guarding.” Scientists are increasingly learning more about why some animals, specifically dogs, have this behavior and how pet parents can respond. 

“Resource guarding is a normal behavior that dogs perform to either get or keep access to an item of perceived value to them. Even though it’s normal, it can be problematic for owners, particularly when aggression is involved,” says Jacquelyn Jacobs, an assistant professor in the department of animal science at Michigan State University.

Resource Guarding Aggression

Resource guarding has also been termed food-related aggression or possessive aggression. It can involve anything a dog feels is valuable, whether that is food, treats, toys, or even stolen items, they know they are not supposed to have — like dirty socks or wrappers plucked from the garbage can.

When a dog is resource guarding, it might display obvious behaviors such as baring teeth, growling, and even biting. But there can also be less noticeable behaviors. A dog might stiffen or freeze, turn its body, walk away with an item, or try to eat the item rapidly, Jacobs says. 

Read More: Dogs and Cognition: How Do We Know If Dogs Have a Sense of Time?

Common Triggers in Dogs

Not all dogs are resource guarders, and Jacobs says there are both genetic and environmental factors. In a 2018 study in Preventive Veterinary Medicine, Jacobs and her research partners surveyed 2,207 pet owners to identify common traits among resource guarders. 

The participants first watched training videos to learn to identify resource guarding behavior. They then answered questions about their dogs’ behavior as well as their home environment. The study found that unneutered males and dogs living in a multi-dog household were more likely to be resource guarders.

There were also some character traits that indicated a dog would be more likely to resource guard. Fearful dogs, as well as dogs who were impulsive, were more likely to get territorial over resources they felt had value. 

“Both generalized fear and impulsivity – the tendency to act without forethought —  are mostly due to genetics,” Jacobs says.

Although resource guarding is an innate behavior for some dogs, others might develop it as a learned behavior. Jacobs says that dogs are very smart and develop behaviors based on past experiences.

These past experiences can come from their time with their mother and littermates. Or it can come from their interactions with humans. If a person, for example, suddenly snatches a rawhide from a dog while they are in the midst of enjoying it, the dog may become possessive of rawhides in the future.

“We are constantly influencing our dog’s behavior, so if we respond to a situation in a way they perceive to be negative, such as by taking the item of perceived value away from them, they may respond more intensely in the future,” Jacobs says. 

Read More: Why Do Dogs Like Certain People And Not Others?

Discouraging Resource Guarding

Recognizing resource guarding behavior is crucial to taming it. A 2017 study in Applied Animal Behaviour Science found that people can identify clear signs of aggression, such as snapping, growling, or biting. However, they miss the subtle clues that dogs use to signal that an item is important and that they want their space. 

“Resource guarding is generally a normal behavior, and most dogs communicate their desire to maintain access to an item very subtly, at least at first,” Jacobs says.

The signal may be as subtle as a momentary freeze or muscle stiffening. Avoidant resource guarders might take the item and walk away.

For pet parents, recognizing these subtle clues is key to understanding the item is of value and not intensifying the situation, especially if the dog is guarding an item they are not meant to have. 

“My own dog is an avoidant resource guarder. She particularly likes to take a sock from my dirty clothes pile and walk around with it in her mouth,” Jacobs says. 

Jacobs’ dog doesn’t destroy the sock but she worries her dog could swallow it. So, she lets the dog have the contraband for a short while before using a treat to initiate a trade. 

“She drops the sock while she goes to get the treat, and then I can take the sock back. It’s important to me that she never feels like my presence is a threat to her, which is why I think she’s never felt the need to escalate to aggression to protect her sock resource,” Jacobs says.

Trading treats for the forbidden item can help de-escalate the situation. There are other management techniques that Jacobs says pet parents can employ. If a dog, for example, is possessive of toys and lives in a multi-dog household, then toys should only be used when the dog is alone with the humans.

“If that’s not possible, then ignoring the dog when they have the item can help to de-escalate the behavior,” Jacobs says. “Showing interest and giving attention can cause the dog to respond more intensely, and perhaps aggressively in the future.” 

For my little resource guarder, ignoring her and her mutilated brontosaurus seems to help. But if she persists, the threat of not being on the couch with the rest of us is enough to calm her down. The couch, it seems, is of far greater value.

Article Sources

Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:

Emilie Lucchesi has written for some of the country’s largest newspapers, including The New York Times, Chicago Tribune and Los Angeles Times. She holds a bachelor’s degree in journalism from the University of Missouri and an MA from DePaul University. She also holds a Ph.D. in communication from the University of Illinois-Chicago with an emphasis on media framing, message construction and stigma communication. Emilie has authored three nonfiction books. Her third, A Light in the Dark: Surviving More Than Ted Bundy, releases October 3, 2023, from Chicago Review Press and is co-authored with survivor Kathy Kleiner Rubin.