Want to Know Why Airplanes Have Little Holes in the Windows?

Here's a fun fact Friday post for ya! Watch this! Thanks Jeremiah for the link!

I've always wondered why there is that tiny little hole in the bottom of airplane windows. It turns out it's got a couple of purposes! Sourced the information from airplane manuals and airmechanic forums. One could make the argument that it's for keeping structural integrity on the outer most pane, but I think the way I described it implies that.