One way to think of Ant Farm, the subject of a recent exhibition at Pioneer Works in Brooklyn, is as the art-world equivalent of an underground music act. They were founded in San Francisco in 1968, against the backdrop of psychedelic counterculture. Despite their impressive back catalogue, they are remembered mainly for two smash hits—Cadillac Ranch, 1974, and Media Burn, 1975. And like so many bands, they have recently reunited, with a slightly different lineup.