I have three bantams in a permanent run. They get fed laying mash, lettuce from the garden and worms from the worm farm. They also get put in a temporary run on the lawn every week or so.
Lately, they've started eating their own eggs! I went out this morning and found them all standing around happily gobbling up yolk; no matter how I yelled or waved they wouldn't leave it.

I've tried the 'fill an egg shell with mustard' trick (twice), given them extra shell grit, ground up their own egg shells and fed them back - nothing so far has worked! Has anyone solved this problem?
Kfish