First, evidence of the slug that broke into my house while I was on holiday:
Somehow I didn't notice this trail across the speaker for weeks. So, judging from other evidence I've found, it apparently came in probably near the windows, went across the speaker, across one of my shoes, up my bookcase, across one of my Powell's bookmarks, which it also nibbled, then on some unknown path across the room to the kitchen area, where it nibbled on a page of recipes before ending up on the wall near the garbage can where it was when I came back and nabbed it and threw it back outside. Yuck.
And yuckier! This is living on the outside of one of my windows which is where it had better stay.
Hard to show the relevant size of the thing, but it's about an inch long. You can easily see hair on its legs! Just before I took this photo, I watched it crawl over and gobble down a mosquito that got caught in its web (which: yay!, but: ew). Right now I can see its web shining in the sun BUT WHERE'D THE SPIDER GO??? *meep*