The time it takes to train a dog for narcotics detection varies. It can be as short as a month but generally takes about six to eight weeks of daily training for certification. The challenge for narcotics dogs is the number of substances they are used to detect. Years ago it was just marijuana, which is very aromatic and easy to smell. With so many more types of narcotics being trafficked, it is more of a challenge. Narcotics dogs are used during shakedowns, when a dormitory is vacated and searched. They are also used for random checks of cars and people. Angola also now uses body scanning machines to help in the detection of contraband.