Crushed egg shells

Previously I have avoided giving egg shells to the hens to eat but some of you have been in touch to tell me my fears that it will encourage them to eat their own eggs are unfounded. We have recently had a few incidents of shellless eggs and in one case, a very small egg was laid. This pointed to insufficient calcium in their diets despite providing them with lots of grit. One of the neighbouring allotment holders suggested I roast the shells and grind them in a pestal and mortar. This also gets around the problem of feeding chickens untreated kitchen waste. Anyway, the video shows all.