Our great Dane does this. If he doesn't want a treat, he'll go and put it by our small dogs' kennels for them to have. He also won't eat treats he likes unless the small dogs get one too.
And, oddly enough, he's the only dog I've ever encountered that can free feed (great Danes are notoriously food motivated). But water, though. We have to chase him away from the bowl or he'll sit there and drink the whole thing.
Between the thousands of years of semi-selective breeding and the parallel evolution that made our ancestors want the selective breeding to happen, the emotional compatibility between dogs and humans is amazing. They're not humans of course, and we do well to remember that, but the connection is eerie, and when you see a dog display that kind of pack/family oriented behavior, it's heartwarming.
Mine would hide his treat until he was ready to eat it. Sometimes he'd hide it in our other dog's bed, then be all shocked Pikachu when it wasn't there later.
Weird. All of my dogs are free feed. While raising them, we always allowed access to a full bowl, and they've never wanted to eat the full thing since they know they'll always have access.
We have a dogsitter when we are on trips. According to her, our heeler would politely take blueberries that were offered and then wander off, returning not long after. It was only later that she found a stash of uneaten blueberries on the couch. My little man was a desperately skinny and frightened stray in a kill shelter before he came to us, and on the theory that whatever makes him feel safe and content is better than the alternative, he's, uhhh, put on weight. If he liked the blueberries, they would not be left on the couch.
The fact that he was a stray could explain that behavior. He may have had a bad experience with wild berries and didn't want to get sick but also didn't want you to feel bad.
Yeah, we always wonder what he had to deal with. He's still very sensitive to any pressure at all on his ribs, and he hoards soft toys in a den (under a bed), though he responds with exasperation rather than anger if one is taken. When we first got him, he tried eating acorns (hell on a dog's stomach, I understand), pre-emptively winced the first time he barked in view of me, and despite generally hating to go outside any longer than it took to potty, climbed up on our patio furniture to investigate the fence the first time we had to leave him with a sitter.
These days, he's fat, which is a negative of course, and he's still an idiosyncratic homebody, but he's also confident enough to ask for affection, isn't reactive to anything other than vacuums, and has a great relationship with our other dog. The turnaround has been lovely, and if being a chonk came as part of it, I think it's a trade worth having made. Our other rescue was born after his mother arrived at the foster, and has a very different relationship with food, exercise, and new people. His super playful but emotionally aware energy has worked well with our "seen some shit" heeler.
The squirrels freak out whenever my cat is outside and I'm sure he'd love to catch one of them, but my feline is simply way too fat for that to be possible. So, he just sits there and stares at them while they make "danger" noises. For some reason, one of the squirrels sounds way more concerned than any of the others. I don't like feeding wildlife, but whenever that high-anxiety squirrel is out there alone, I give him a couple unsalted peanuts as an apology for having to put up with my cat.