Diehard cheeseheads will know this but some of you will find this bit of science interesting, perhaps…
Excerpt from HuffPo:
Contrary to what you may have been told when you were a kid, the holes in Swiss cheese are not made by mice nibbling away at a big wheel of Swiss. As sweet (or gross) as that image may be, the reason for holes in Swiss cheese (known as “eyes” in the cheese world) is a bit more scientific and a little less “cute.”
read on at Why Does Swiss Cheese Have Holes?.