Bees training to sniff out land mines
By Darko Bandic of Associated Press
In Croatia, researchers believe bees could replace humans in land mine detection.
ZAGREB, Croatia — Unlikely heroes may be coming to the rescue to prevent similar land mine tragedies: sugar-craving honeybees. Croatian researchers are training them to find unexploded mines littering their country and the rest of the Balkans.
When Croatia joins the European Union on July 1, it will bring numerous un-cleared minefields to the bloc’s territory. About 466 square miles are still suspected to be filled with mines from the Balkan wars in the 1990s.
Nikola Kezic, an expert on the behavior of honeybees, outlined the idea for the experiment: Bees have a perfect sense of smell that can quickly detect the scent of the explosives. They are being trained to identify their food with the scent of TNT.
“Our basic conclusion is that the bees can clearly detect this target, and we are very satisfied,” said Kezic, who leads a part of a larger multimillion-euro program, called “Tiramisu,” sponsored by the EU to detect land mines on the continent.
The method of training the bees by authenticating the scent of explosives with the food they eat appears to work: bees gather mainly at the pots containing a sugar solution mixed with TNT, and not the ones that have a different smell.
Kezic said the feeding points containing the TNT traces offer “a sugar solution as a reward, so they can find the food in the middle.”
“It is not a problem for a bee to learn the smell of an explosive, which it can then search,” Kezic said. “You can train a bee, but training their colony of thousands becomes a problem.”
Croatian officials estimate that since the beginning of the Balkan wars in 1991, about 2,500 people have died from land mine explosions. During the four-year war, around 90,000 land mines were placed across the entire country, mostly at random and without any plan or existing maps.
Dijana Plestina, the head of the Croatian government’s de-mining bureau, said the suspected devices represent a large obstacle for the country’s population and industry, including agriculture and tourism. In the nearly two decades since the end of the war, land mines have taken the lives of 316 people, including 66 de-miners, she said.
“While this exists, we are living in a kind of terror, at least for the people who are living in areas suspected to have mines,” she said. “And of course, that is unacceptable. We will not be a country in peace until this problem is solved.”
It may be a while before the honeybees hit real minefields, Kezic said. First, they will conduct controlled tests, with real mines but which are marked.
Kezic said American researchers have in the past experimented with mine-searching bees, but TNT — the most common explosive used in the Balkan wars — wasn’t part of their experiment because its smell evaporates quickly, and only small traces remain after time. Rats and dogs are also used to detect explosives worldwide, but unlike bees, they could set off blasts on the minefields because of their weight.
Even after the de-miners have done their job in an area, some land mines are missed and remain in the soil, and they are most often the cause of deadly explosions. Once the experiment with bees proves scientifically reliable, the idea is to use them in the areas that have already been de-mined, where their movement would be followed with heat-seeking cameras, Kezic said.
“We are not saying that we will discover all the mines on a minefield, but the fact is that it should be checked if a minefield is really de-mined,” he said. “It has been scientifically proven that there are never zero mines on a de-mined field, and that’s where bees could come in.”