It is like my two guineas are the only ones eating the oyster shell. I do sell my guinea eggs every once in a while. I went to my friends house yesterday and he complained to me about the guinea eggs. I sold him a whole dozen for a buck! Well, the shell is sooo thick that we threw the eggs to each other and they didnt break. We also let them fall on the ground and they didnt break untill after like five throws and five hits on the ground. Why are the guinea's eggs soo thick? Thanks! Cody!!