I didn't really think anything of it when we started getting 2-3 eggs from 5 hens when usually we got 5-6. I just went out in the garden because after looking out the window I could only see 4 hens. After hearing low purring and clucking I looked in a bush to find one of my girls surrounded by about 15+ eggs. Its gonna be one hell of an omelette that's for sure..
Your hen is very probably broody, where she is trying to hatch chicks whether or not you have a cockerel in your flock, when you went near the hen did it puff up its feathers and make a deep clucking or purring noise?
It was just a low purring, she was up and about with the rest of them after about half an hour though