According to a recent issue of Popular Mechanics (July 2011), Inscentinel, a public company funded by the British government, has developed an unusual bomb sniffing device. The device uses 36 live honeybees, if you can call this living, who have been specially trained to identify a host of bomb materials including C4, Semtex, and Dynamite (TNT).
Conditioned within a matter of minutes to associate their feeding with the above mentioned explosive ingredients, when smelled, the bees will extend their proboscis toward the anticipated food, crossing an infrared beam in the process. If enough of the bees cross the infrared beam simultaneously, an alarm is triggered. So sophisticated are these honeybees in picking up a scent, the prototype device is reported to be more sensitive than any known bomb detection device currently in use— in the parts per trillion range (1 followed by 12 zeroes!).