In the training world, it's something of an adage that dogs do not know that what they're doing is naughty. I know it's because most people have misconceptions about canine behavior, so a sweeping generalization of "They just don't know" works better than "Well, they generally don't know but sometimes they do". Dogs don't poop in the house out of spite. They don't tip the garbage to get back at you for leaving them alone. Dogs do these things because:
a) they were not trained to NOT do them
b) they were trained that it meant something else
c) they are scavengers and opportunists by nature.
d) there's something medically wrong
And 99% of "misbehavior" can usually be traced to those four things. Usually because their person inadvertently taught them that, like by chasing and shrieking at Fido while he wig-digs around the living room in front of your grandma with your red lacy thong clenched firmly in his teeth. You taught him it's a game, not that it's naughty.
But some dogs... some dogs KNOW that it's naughty. Some dogs know how to manipulate events and use active deception to fool you. SOME DOGS revel in this behavior. Just because they can.
I own one of those dogs.
Not every "naughty" thing he does is deliberate. Most of it falls under one of the above categories. I know him well enough, though, to know when he's about to do something. There's a glint in his eye, a subtle change in tail set, an altercation in his stride. If I'm really good, I can short-circuit his half-formed thought before it becomes a plan.
Usually I'm not that good.
Last night I was going thru the mountainous pile of mail from our week vacation, creating piles for recycling, shredding, reading and filing. Lucky had just finished dinner and was standing and staring at me, one of his favorite past times. Clearly bored with trying to creep me out with his strangely human regard, he trotted out of the kitchen. I saw the tail end of him as he went around the corner and up the stairs and thought "Oh no". Cause his flag was up and over his hips, blazing as brightly as a nautical signal flag. I know what that means. It means he's looking for socks. Or underwear. But preferably socks.
We've never engaged in chasing him when he stole things like that as a puppy. We knew that would make it a game. We would either ignore these antics until he gave up or we would calmly trade him a real toy for the stolen item. The thing is - he doesn't want to be chased. He just wants to interrupt whatever you're doing. He doesn't even necessarily want to play when you've broken away from your other task. Even making eye contact with him is enough satisfaction - he knows he got you, so he'll drop the item and walk away. He's just being naughty to be naughty.
Sure enough, about 60 seconds later I hear thundering paws coming down the stairs at 50 miles an hour (because he gets louder and more brazen when he's gotten into something naughty, the better to get your attention). He went tearing around the far corner towards the family room, full body wags engaged. I glanced up to see what he'd gotten and it was a pair of my underwear. I continue opening envelopes, waiting to see how long it would go on before he tired of it or I had to intervene.
And he's putting on quite the show. He's shaking his head all the way from his shoulders in big, woggly swoops all the while he's dancing and prancing, leaping and crouching, circling around, dipping down, bouncing up. It's like watching some canine rain dance, only he's probably hoping it will rain socks.
Finally, he leapt a full five feet, giving his head a huge shake mid-leap. He landed in a play bow facing the ottoman and my underwear landed 5 feet behind him. He held the playbow, staring in front of him, for a good 5 seconds before slowly swinging his head to look at me. Because I am giggling hysterically. I couldn't help it. The Spouse was laughing too.
Mission accomplished, he spun in a circle on his hind leg and sprinted to catch the underwear up. Giving in to the inevitable, I walked over to him and he dropped into a play bow. I told him to drop - he did, stood up, and backed away, wagging his tail happily. I retrieved the underwear and he trotted off to settle down with a bone to gnaw on.
Sometimes they do know.