I have a friend who is a fisherman and he used to bring his surplus maggots after fishing, the plain ones were fine but some were bright red and they stained the yolks . they had been fed a dye and it transferred, I even had one to a vet before we realised what it was.
Not bad, puts you off...
Sprouted whole oats/ barley/ wheat.
Mine absolutely adore warm cooked rice. hot mash etc is good in winter when its cold.
Cauliflower leaves
worms or maggots ( fishing bait, not the coloured ones tho, just plain white, the red ones will colour the egg yolks blood red)
Melon or pumpkin seeds.