There are many theories on why dogs enjoy playing fetch. Some people think man's best friend retrieves balls, sticks and other objects just for the fun of the game.
Canines enjoy running and interacting with people, so when they bring the object back, they're rewarded by getting to chase the item again.
Other animal behaviorists think a love of the game can be traced to canines' ancestry. Just as wolves chase down their pray and bring it back to share with their pack, perhaps dogs instinctually do the same with sticks and balls.
Regardless of the reason, there's no denying that most dogs love a game of fetch. And as the videos below prove, some dogs love fetch so much they'll play it alone — or even attempt to play with babies and statues.
Why won't this guy throw the stick?
No human required
Dog's DIY game of fetch
Gotta train them while they're young
No eyesight required
Four hands and not one will throw the ball
It's slippery out there
How to keep a dog occupied for hours