Eight newborn springer spaniels already have their careers mapped out for them - helping the police detect explosives. And they'll be following in the footsteps of their parents Bowie and Kilo, which are also explosives search dogs in the police dog unit. The five male and three female puppies, born on March 22, are being fed by mother Bowie in their kennel and cared for by officers in the unit's headquarters in Sheung Shui. James Lee Cheuk-wai, the unit's chief inspector, said puppies were used to replace retiring police dogs which would withdraw from service when they turned nine years old. "We have to keep an eye on the number of retiring dogs ... to decide when to start breeding," he said. The puppies were named Happy, Hero, Horace, Howard, Hydro, Hazel, Heidi and Helen by a group of visiting students last week. Before the handover, British army dogs were used to detect explosives while police dogs were used mainly for patrols and drug detection. Police started to breed their own explosives search dogs in the 1990s and took over the job in 1997. As of February, the unit had 101 dogs, of which 11 were trained to search for explosives. Lee said springer spaniels were used to detect explosives because of their agility, keen sense of smell and relatively small size. Those who enjoyed searching as a game would be better suited for the job. One such dog is Leon, now serving at the airport with his handler, senior constable Eva Tsung Wai-ling. Tsung and Leon, aged 6-1/2, have co-operated in major events like the 2008 Olympic Games equestrian events and last month's Rugby Sevens. The pair also worked together during visits by state leaders. At about the age of one, Leon underwent an eight-week course in which he was taught to detect different types of dynamite. He was given a tennis ball whenever he succeeded. "The ball is his reward. He sees searching for explosives as a treasure hunt," Tsung said. But luckily, Leon has never found any explosives on the job in Hong Kong.