In all the years we've been co-existing with chickens, we've never had a bird get broody enough to actually sit on eggs for any substantial length of time. And even if one had gotten broody, before we had Captain Fluffybutt, it wouldn't have mattered anyway (insert lecture on the "birds and the bees" here).
But now...we have "Peep," our little bantam hen, who went broody one week ago and has been sitting on her eggs ever since. Tonight we candled the eggs to see if any of them are fertile...(I bet the makers of the iPhone never imagined the flashlight feature would be used for this - but it was perfect for it!).