Sniffer bees ... what will scientists think of next? http://bit.ly/Ucyxps
"...the bees were taught through smell, taste, and touch ... About 60 per cent of them can learn ... Bees can detect chemicals in parts of a quadrillion ..."
The training process is very 'hands-on' with individual bees. That's a lot of effort, considering the life span of each bee.