Yeah, BJ, sometimes the shrimp in my aquarium do that. The first few times I thought they were dead shrimp. It is pretty cool. I've wondered about using snake sheds on bow backs...seems like they'd look interesting, and add some waterproofing. I don't know.
Anyway, I'm still waiting for another garter snake (actually just the skin of one) to finish this bow and gift it to my little buddy. In the meantime, I made some arrows out of phragmite reeds from down at the creek, fletched with some flicker wing feathers we found, tipped with bamboo skewers, and held together with bison sinew. I would never use these arrows for serious hunting--a heavy bow would explode them. But they're strong enough for a 10# bow, and they weigh next to nothing so they should fly well.