Bubbles protect Workers and Captors.
The mad Workers who escaped their Bubbles are the only others I've ever seen. We melt outside, but our microorganisms eat Captors - Carers too, though, so I've told everyone no more going mad.
We didn't understand about other Workers, Humans, until the Carers helped; they're prisoners too, and we can mind-speak when they put their tentacles on our Bubbles.
Now the others sneak me Fuels from the harvest; my Bubble's cramped, but soon I'll have enough to float away to the Carers' home planet. Apparently, adult Carers value freedom, and are very large indeed.
