I think the answer to that question becomes even more hazy when you come across articles such as this one, in which bees are said to take ten minutes to train to become explosive detectors as opposed to dogs who take three months.
Here is another, slightly more detailed article on the subject.
While I found this article both fascinating and thought-provoking I did wonder how well they'd thought the venture through. It seems the bees would be easily addled by honey based decoys and prompted to lose their stingers in the presence of insecticide. Am I just attributing to much foresight to explosives planters?
Anyway. Check out the articles. It's worth a read.