Here is an extract from a web article on research on using bees for sniffing out explosives
The beauty of the device is that the bees are unhurt. A few hours of training and a couple of days later, the bees are released back to their hives and reintegrated back into bee society. Each bee is individually trained to recognize a different smell so hypothetically, the 36 bees contained in one handheld device could replace the far less cost-efficient bomb sniffer dog.
I was interested to see that the work is being done in my home county, Hertfordshire (UK). Not that it really matters, a long as technology of this kind is developed to the stage where widespread uptake is practicable, initially in mine detecting, presumably, but later in airports and in locating terrorist bomb factories . Here is the link:
My impression is that this kind of work is going on worldwide and at quite a pace. If you know of any reports I am sure some of the readers would be interested. So please email me at firstname.lastname@example.org