Imagine an insect repellant that not only is thousands of times more effective than DEET -- the active ingredient in most commercial mosquito repellants -- but also works against all types of insects, including flies, moths and ants. That possibility has been created by the discovery of a new class of insect repellant made in the laboratory of Vanderbilt Professor of Biological Sciences and Pharmacology Laurence Zwiebel and reported this week in the online Early Edition of the Proceedings of the National Academy of Sciences. "It wasn't something we set out to find," said David Rinker, a graduate student who...