How are bomb dogs trained? To teach Brandy to recognize the six basic odors of explosives, McMurray says, he used a method called “odor imprintation.” He placed 20 different odor combinations in Brandy’s toys and played fetch. Eventually, he hid the bomb odors in small cans. As methods of concealing explosives evolve—including using shoes, as Richard Reid is accused of doing on a flight last December—so does the training. “We began putting small cans with odors in volunteers’ socks,” says McMurray. “Now I say ‘shoes,’ and Brandy searches low.”