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Why do dogs love to play with trash? – Sarah G٫ age 11٫ Seguin٫ Texas
When I think about why dogs do something, I try to imagine what motivates them. What does a dog get out of playing with trash? As a veterinarian and a professor who teaches college students about companion animals, I believe there’s an easy answer: Garbage smells delicious and tastes good to dogs.
Dogs have an amazing sense of smell. They have 300 million receptors for smell in their noses, while humans have only 6 million. People can make use of this sniffing ability to train dogs to detect illegal drugs, explosives and endangered species, and to help locate people lost in the woods.
While you might not like how your trash smells, to your dog it is an appealing buffet brimming with apple cores, banana peels, meat scraps and stale bread. Even used napkins and paper towels are tempting to dogs, when they are smeared with and carry the smell of yesterday’s lunch.
Because dogs can find trace amounts of explosives or a person buried under 6 feet (1.8 meters) of snow after an avalanche, they are certainly capable of locating last night’s pizza crust and chicken bones in the kitchen garbage can.
Sometimes it’s hard to see what the attraction is. My Australian cattle dog mix, Sparky, loves to eat used tissues – gross, right?
Even empty cans smell inviting to dogs. Trash cans in kitchens and bathrooms are often at their nose level, too, making for easy access. Add to that the fact that if the dog got into the garbage once and found something tasty, they will likely keep searching with the hope of being rewarded again.
A Colombian police officer uses a drug-sniffing dog to search packages of flowers prior to export at El Dorado International Airport in Bogota on Feb. 5, 2025.
Raul Arboleda/AFP via Getty Images
Thrill of the hunt
Searching and digging around for food is natural for dogs because it provides some of the thrill of the hunt, even if they just ate and aren’t hungry.
The most successful prehistoric dogs ate the bones and scraps that humans left behind more than 10,000 years ago. Hanging around humans and their garbage was a way they could get plenty to eat. Even your pup today has some of those same old searching instincts.
While our trash has changed from the days of hunting and gathering, the discarded paper napkins, plastic wrappers and food scraps we throw away all still smell like food to dogs. And this scavenging behavior is still hardwired in our pampered pets. Although it may look to us like they’re playing, our dogs’ sniffing out and tearing things up from the trash and tossing them around mimics what their ancestors did when they tugged on and tore up an animal carcass they had found.
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