There was water damage from decades of minimal maintenance. Basically water was getting where it wasn't supposed to be, leading to rotting wood which in turn attracted ants. It wasn't as extensive as on the east part of the farmhouse, but I still had to brace up the floors and start cutting rotted wood out.
(Click on any image for a larger picture)
Things can take longer than I'd like. For example I thought I could install the window(s) in one day. Once I opened up the wall and had a look at the rot, I had to fix that. To date, I've worked three long days on this project. I still have to install the kitchen window, shore up the foundation with i beams, and put on the rigid insulation/siding.