Reuters) - Two young brothers found dead in an apartment over a reptile store in New Brunswick, Canada, were believed to have been strangled by a snake that escaped its enclosure and slithered into the building's ventilation system, police said on Monday. The boys, ages 5 and 7, were sleeping over at a friend's apartment above Reptile Ocean in the city of Campbellton. Their bodies were discovered on Monday morning, said Constable Jullie Rogers-Marsh of the Royal Canadian Mounted Police. "It's believed the two boys were strangled by the snake," Rogers-Marsh said, adding she was unaware if the boys were asleep when the attack occurred. The snake, which was recovered in the building by the store owner, was in the custody of police, who would not identify its species. View gallery." An escaped snake is thought to have strangled two young brothers found dead at an apartment in Canad â€¦ "At this point we are still trying to piece together what happened," Rogers-Marsh said. "We do know the brothers were sleeping together in one room and the friend was sleeping in another." Experts say attacks by exotic snakes are extremely rare. "It's really not in their nature," said Terry Phillip, curator of reptiles at Reptile Gardens, a wild animal park in South Dakota. "Snakes, even large pythons, are far less dangerous than family pets like dogs," he said. Reptile Ocean did not respond to a request for comment. On its official Facebook page the retailer calls itself "an exotic pet store open to the public for purchase and viewing." An autopsy on the boys was planned for Tuesday.