There are many good reasons to leave town in July. The sun is relentless, the humidity high, and afternoons are plagued by sudden thunderstorms of biblical proportion. But those who migrate north miss out on the splashy summer transformations at Miami Metrozoo. Chill out at the chimpanzee-activated sprinklers: When the primates pull a handle, they douse visitors in the S.O.A.C. (Sprinkler Offense Area/Chimpanzee) Zone. Cooling mists also provide wet relief between glimpses of other exotic animals. And there's a new giant water-shooting mushroom near the spotted hyenas, in addition to the spouting frog, pink flamingo, and seahorses around the park.