With her nose in the grass of a Bosnian field, Orna sniffs furiously until she finds her target. She then sits and wags her tail in excitement for the red rubber toy that is her reward.
The exercise is only a game for the two-year-old dog, but the mine-detection skill is saving lives in Bosnia and around the world.
The Balkan state, still working to rid its territory of landmines dating back to its 1990s war, has become an important training ground for canines deployed as far afield as Asia, Africa and the Middle East.
At the end of Bosnia's 1992-95 conflict, some eight percent of its territory was littered with explosives.
Today, experts believe it is down to two percent, thanks in part to the work of the dogs, who have learned the trade at two centres backed by US and Norwegian NGOs.
Orna, a black and brown Belgian Malinois, is undergoing her schooling at the global training centre of the Norwegian People's Aid (NPA) in a suburb of Sarajevo.
She is among 40 dogs from the hard-working breed currently in training, while 30 other "veterans" are "enjoying their well-deserved retirement", said Gordana Medunjanin, who works at the centre.
All the dogs are the Malinois breed, which is known to be "energetic, adaptable and have a great desire for work and cooperation", she said.
The site's graduates are currently taking part in mine clearance programmes in Bosnia, Iraq, Lebanon, Somalia, Zimbabwe and Cambodia.
-'It's a game'-
Training starts when the puppies are four to six weeks old and lasts up to 18 months, said Orna's trainer Namik Dzanko, 29.
One of the important first tests is to confirm the dog's interest in the rubber toy, known as a cong, that helps motivate their work.
The dogs then start honing their skills by detecting the scent of explosives, hidden at random in tin canisters attached to a merry-go-round.
The dog circles the structure, stops and sits when it sniffs a mine.
Successes are rewarded with some play time with the red toy.
More advanced training continues in the simulation "minefields" outside, where explosives lacking detonators are buried in a 100- square-metre (1,076-square-foot) plot, with zones delineated by yellow tape.
Guided by their trainers, the dogs methodically sniff in straight lines.
When they pick up the scent of the explosive, they "mark" it by sitting quietly and pointing their muzzle at the suspected spot.
At a real minefield, the area would then be inspected by a de-mining expert.
"The dog does not understand that he is looking for a mine and that it is dangerous. For him, it's a game," said Dzanko.
"He finds something and is rewarded with his toy. Through this positive experience, he does a job which saves lives around the world."
The dogs are used mainly to clear suspicious areas around a known minefield, though they can be sent into the "heart" of the area, if the precise locations of the explosives are unknown.
Using dogs for the perimeter helps save time for the de-miners, said Nermin Hadzimujagic, whose US-funded Mine Detection Dog Center in southern Borci has sent pups on missions to places like Afghanistan, Kosovo and Lebanon.
"On a working day, a de-mining expert can inspect an area of 70 to 100 square metres, while a dog can cover up to 1,000," he added.
- 'Like footballers'-
Bosnia's goal is to be mine-free by 2025.
More than 500,000 inhabitants, or 13 percent of the population, still live close to dangerous areas.
Since the end of the war, anti-personnel mines have killed 617 people, including 53 de-miners, according to the Bosnia and Herzegovina Mine Action Center.
No mine-sniffing dogs trained in Bosnia have ever been killed, in the country or in missions abroad.
The dogs are tested twice a year and must perform flawlessly.
"Otherwise, they cannot be used in de-mining anymore", Hadzimujagic, 44, said.
"If the dog misses a mine and someone has an accident tomorrow, we are accomplices," stressed Emir Cukas, a dog trainer in Bosnia's civil defence de-mining unit.
Dogs can work for a dozen years if they are healthy, but a lifelong training is crucial, he said.
"They are like footballers, like all sportsmen. If you train every day, you are good."