These five cloned dogs, all named Toppy, are following the bouncing ball as part of their training to be drug and explosive detecting dogs in South Korea.

The country that created the world's first cloned canine plans to put duplicated dogs on patrol to sniff out drugs and explosives, the Associated Press reports.

"Toppy" is a combination of the words "tomorrow" and "puppy",

The Korean Customs Service unveiled Thursday seven cloned Labrador retrievers -- the other two are also Toppys -- being trained near Incheon International Airport, west of Seoul. The dogs were born five to six months ago after being separately cloned from a skilled drug-sniffing canine in active service.

Officials say using clone dogs for the tasks could help reduce costs.

The cloning work was conducted by a team of Seoul National University scientists who in 2005 successfully created the world's first known dog clone, an Afghan hound named Snuppy.

"They have a superior nature. They are active and excel in accepting the training," said Kim Nak-seung, a trainer at the Customs Service-affiliated dog training center. In February, all seven dogs passed a behavior test aimed at finding whether they are genetically qualified to work as sniffing dogs. Only 10 percent to 15 percent of naturally born dogs typically pass the test.

If the cloned dogs succeed in other tests for physical strength, concentration and sniffing ability, they will be put to work by July next year at airports and harbors across South Korea, according to the training center.