WHY DO DOGS LOVE TO PLAY WITH TRASH?

When I think about why dogs do certain things, I try to understand what motivates them. Take playing with trash, for example. As a veterinarian and a professor who teaches college students about companion animals, I believe the answer is simple: Garbage smells delicious and tastes good to dogs.

Dogs have an extraordinary sense of smell, with 300 million scent receptors in their noses, compared to the 6 million that humans have. People often use this incredible sniffing ability to train dogs to detect illegal drugs, explosives, and even endangered species, or to help locate missing people.

While you might find your trash unpleasant, to your dog, it’s like a gourmet buffet filled with apple cores, banana peels, meat scraps, and stale bread. Even used napkins and paper towels, with traces of yesterday’s meal, are enticing to dogs.

Given that dogs can detect tiny amounts of explosives or locate a person buried under 6 feet of snow after an avalanche, it’s no surprise they can easily sniff out last night’s pizza crust or chicken bones in the kitchen garbage can.

It’s not always easy to understand the attraction. For instance, my Australian cattle dog mix, Sparky, loves eating used tissues—gross, right?

Even empty cans have an enticing smell for dogs. Trash cans in kitchens and bathrooms are often at nose level, making them easy targets. And if a dog has ever rummaged through the garbage and found something tasty, they’ll likely keep searching, hoping for another reward.

Thrill of the hunt

Searching and digging for food is instinctual for dogs, providing them with a bit of the thrill of the hunt—even if they’ve just eaten and aren’t hungry.

The most successful prehistoric dogs thrived by eating the bones and scraps left behind by humans over 10,000 years ago. Hanging around humans and their waste was a way to find plenty of food. Even today, your dog retains some of those ancient searching instincts.

While our trash has changed since the days of hunting and gathering, the discarded paper napkins, plastic wrappers, and food scraps we throw away still smell like food to dogs. This scavenging behavior is hardwired in our pampered pets. While it may seem like play to us, when dogs dig through the trash, sniffing, tearing things up, and tossing them around, they’re mimicking what their ancestors did when they tugged on and tore apart animal carcasses they had found.

Many people take advantage of this instinct by using “snuffle mats”—cloth or paper where food is hidden—or puzzle feeding toys to engage their dogs’ minds. Hunting for and finding their food allows dogs to use their noses and sharpens their natural skills.

Annoying or even dangerous

While it’s natural for dogs to spread trash around the house, cleaning it up is never fun for their owners. Plus, if your dog rummages through the garbage, it could be putting itself in danger. Eating plastic bags, string, chicken bones, chemicals, or rotten food can lead to blockages, diarrhea, and poisoning. Known as “garbage gut,” this kind of poisoning can be life-threatening.

I’ve treated dogs that injured their mouths or tongues on cans or broken glass. I once even had to perform surgery to remove a corncob from a dog’s intestines that he had eaten a month earlier. He was certainly relieved when he woke up.

How can you keep dogs away from the trash?

Training a dog to stay away from garbage can be challenging, especially if they’ve found a tasty treat or two by raiding the trash in the past. I recommend investing in a garbage can with a lid that latches securely—one that they can’t open. If that doesn’t work, consider storing the trash, especially food scraps, out of reach in a closet, cupboard, or behind a closed door.

At my house, all the trash cans are behind closed doors, and the bathroom doors are always shut to prevent my cat, Penny, from unrolling the toilet paper. But that’s a whole other story. Our kitchen trash is kept in a latched cupboard.