The first time I shopped in a French supermarket after I moved back from the US, I spent a good 10 minutes looking for eggs in the refrigerated aisle before remembering that we don't actually store our eggs there. That's because European eggs are processed differently from American ones.
To fight salmonella, the US washes its eggs — a process that also removes a thin cuticle coating on the egg. In France and other European countries, chickens are vaccinated against salmonella instead. That way, the eggs keep their coating and don't need to be refrigerated.