"Thought of the day"....Why do hens lay unfertilized eggs?

Following on from this weeks blog about all things eggy - today's thought is ..."Why DO hens lay unfertilized eggs?"
It seems like quite a wasteful process, don't you think?  All that protein, fat, nutrients, calcium that go into the making of one hen's egg - what is the point in going to all that trouble if there will be no offspring at the end of it? 
Here are a few of my thoughts on the matter...

Frogs eggs are fertilized outside the female body (photo credit : George Grall)
So there you have it, these are some of my thoughts on the subject.  I am not suggesting that any of these points are backed up with scientific findings.... the are just the random thoughts of this simple scientist! Maybe you have your own theories to add?

...just a thought!