Batshit crazy

This is my new favorite phrase. I don't actually use it out loud that much since it isn't very appropriate at work or in front of the kids. How embarrassed would I be if they started running around saying things were BSC? I mean, yeah, its funny, but then I look like the asshole mom. Anyway, I don't actually say it much, but I think it a lot. Like "this economy is BSC" or "I'm going BSC" or "dude, that is a BSC idea." Also, it has turned up in songs and stuff like that recently, so I feel one with it. I tried to look up the etymology of the saying but the best I could do was illness brought on by bat guano, which I really doubt is correct.