In remarkable just-completed field trials, scientists have harnessed the insect's powerful sense of smell to track down samples of TNT, Semtex, gunpowder and other explosives hidden in shipments passing through a busy cargo airport.

The project is the result of five years of government-funded research carried out by scientists from Rothamsted Research Centre in Hertfordshire.

The prototype under trial consisted of a shoebox-sized device nicknamed the "buzz box", containing three trained bees harnessed into a removable drawer. An electric fan draws air into the box, while a video camera records the bees' response, which can alert the handler to even the faintest trace of explosives.