Perhaps he's not so stupid. Fresh eggs are tasty.
He is a She, and she is not a happy puppy anymore. She is back to wearing a hard muzzle whenever she goes outside. It is hard to pick an egg up when you have a muzzle on.
I just wish I could be assured every egg she steals is fresh. We find nests around here from last year now and then. We wear "protective" clothing and use a Looooooong pole with a soup ladle taped to it to pick these eggs up. Some have been know to explode as soon as we touch them. We found one nest and went to get the "OSHA approved rotten egg demolition equipment and protective gear" and came back to find the nest empty of eggs. No proof "she" took them, but circumstantial evidence points to her.