Castaways of New Mojave — David Brin

Interstellar kidnapping… or opportunity?A thousand teens and their teachers were stunned when the alien Garubis yanked Twenty-Nine Palms High School right out of California's Mojave desert, plopping it into a jungle many light years away. It was supposed to be a “gift” -- a new settlement for humanity. But tell that to Mark, Alexandra, Barry and Sophie when strange parasites attack… and they don't know what to eat… and the island of Earth-buildings runs out of water!Some claim to have spotted strange tool-users in the forest. Are the Garubis back? Or is this some other possible alien menace?Whatever the skyjacked teenagers and their small number of adult companions face, they will need guts, ingenuity, hard work… and luck! But maybe the worst threat will come from the former students themselves. From basic human nature.