I read today that there are more chickens than there are humans. I thought "really"?! And actually, the world population of chickens in 2003 was 24 billion. So officially maybe 4 chickens for each of the 6 billion living humans on the planet.
There'll be many species greater in number than humans.. but you'd expect them to be smaller than chickens??
Wikipedia states that eggs in shops are likely to be fertilized - but other expert sources disagree. Bit of a chicken and egg situation here..
Wikipedia on Eggs
Wikipedia on Chickens