And in the, "why'd it take this long?" category we have hermit crabs with glass shells. The initial links make it seem like it was a New Zealand university that thought this up, but the only place I found video makes me think someone beat them to the punch by a few years. I would think the critters would be freaked out but apparently they really like being able to see out while safely tucked in their shell. When you're on the lower end of the food chain, it makes sense.