WISCONSIN DELLS, WI—In an annual ritual as regular as the arrival of summer itself, the nation's waterslide tunnels were purged Monday of all the bats inhabiting them. "Go on, scram," the nation's broom-wielding water-park employees said to the bats, which took up residence in the dim fiberglass tubes shortly after Labor Day last year. "Go make your nest somewhere else! It's summertime. There are all kinds of kids who are gonna want to cool down, splash around, and enjoy themselves. So beat it!" Following the successful evacuation of the bats, the water parks' junior employees were sent into the bathrooms to clear out all the daddy longlegs and porcupines that had wintered there.