Good story! We've had similar "issues" with the local fauna in the lakes here in Texas, Perch are the main culpret, I believe. Nothing like the mob attack you experienced, but a few of us have felt those tiny teeth taking little nips out of our ears. They may be small, but they can be pretty aggressive, as a couple of students discovered when the divemaster leading them on a tour had a stream of blood gently rising from one ear after just such an encounter. We all tend to use hoods these days, no matter what the water temperature, we just don't necessarily tell the new students why, don't want to put them off before they even get in the water.