I have a food-obsessed Lab/Ridgeback mixed named Lulu.
Lately the dumbest thing she has done is to get into our litter robots (automatic litterbox) and EAT the litter. Yes, I know lots of dogs will eat cat poo, but these litterboxes are automatic and there is NO poo to eat. She actually eats the litter itself. I use a wheat-based, non-clay cat litter that looks kind of grape nuts cereal...apparently she thinks it is delicious an will eat pounds and pounds of it every chance she gets.
So I spend lots of time coming up with new ways to keep the litterboxes out of her reach...oh, and cleaning up the mountains of poo she passes after eating all of that litter!
The absolute dumbest thing she's ever done, though, happened when she was just a few month old. I used to keep their food sealed in a rubbermaid trash can on the back porch. One day she knocked it over while we were at work, somehow got the lid unlatched, and had herself a feast.
When we got home she was so full that she looked like a balloon. She was so bloated she could not stand up, but could not lay down or sit either. She just waddled around in this painful looking crouch looking guilty.
We had to spend the night on the phone with the emergency vet, staying away to make sure she was going to survive her extra large meal. To this day I am dead certain that if there had been any more food left in the container she would have been dead because she would have kept right on eating.
Now we store the food in a Lulu-free zone!