Bee bomb

Specially trained sniffer honey bees are being used in a successful new prototype that is about the size of a hand held vacuum cleaner. Training the bees is simply a matter of bribing them with sugary treats. Trainers expose the bees to the odour, like the smell of explosives, for a few seconds and simultaneously give the bees a sugar syrup reward.
After 4 or 5 exposures the bees associate the odour with the reward.Consequently, if the bees are exposed to an air sample containing the substance, the bees demonstrate the Proboscis Extension Reflex response, that is they stick out their tongue in expectation of food, which the trainers can observe and then they can respond to the threat.