Today, I learned that hydrometers do not like being dropped from aproximately 2 feet up. I also learned that hydrometers, when they are dropped from aproximately 2 feet up, like to crap little tiny balls.
My daughter dropped mine from about that far and I got lucky. It hit right on the bottom and broke that little "nipple" off the end. It still works though. When I saw it happen I was sure I was screwed.