Eggs in my local supermarket have written on the box "Eggs have no added hormones or antibiotics". I can see how you would give a chicken hormones/antibiotics but can't see how you would do it to an egg.

So is this just as it looks a marketing trick where they have likely pumped the hens full of hormones/antibiotics, but disingenuously claim they haven't done so to the eggs themselves?
Or does this mean neither the eggs nor the chickens that laid them have hormones/antibiotics?

The thing is the more expensive "organic, free range" eggs make the same claim, I haven't seen any that claim their hens have not been given hormones/antibiotics. The claim is always made for the eggs.

I'm in Australia.