There were approximately 3,700 female concentration camp guards from a total of 55,000 personnel. They were trained at Ravensbrück after 1939 and began being used at Auschwitz from 1942. Methods of recruitment varied; some had little or no previous work experience, or came from tertiary professions such as factory line workers, ticket collectors, entertainers, or the nursing and teaching sectors. The SS also placed adverts in newspapers, or ‘headhunted’ particular women known to them through their files. Initially, training could last for as long as six months, but towards the end of the war there was barely any. Male guards were told to view their female colleagues as equals, not subordinates, and many were promoted to head guard or overseer.