Not a single habit of the Dayak shocked the colonial rulers as much as the headhunting. It was considered as 'the most uncivilized' side of the 'wild humans'. Even the Brooke-dynasty of 'white raja's, which were very charmed of the Dayak culture, prohibited headhunting on their territory. However some sources say that Brookes allowed big headhunting expeditions when it was politically of military needed.
The headhunting trips of the Dayak however, had a strong ritual meaning. They brought up slaves, which were later on used as sacrifice for the gods. Beheaded people played an important part in dozens of rites: marriages, funerals, approval of longhouses, planting of rice and the completion of a woodcarving. On the whole a human sacrifice brought the village better times. Some heads - after being stripped, boiled and sometimes decorated - even served as temporary stay for spirits, which were praised during special sacrifices.
By beheading someone, young men showed their courage and also showed themselves to young females and their colleagues. Once he had beheaded someone, he was allowed to wear special tattoos and decorations, like the teeth of a leopard. Headhunting trips formed the best test in which talented people of the village were remarked.
An headhunting expedition on the whole was a well-prepared expeditions, in which many warriors participated, under the rule of an experienced commander. Some armies counted several thousand soldiers, but smaller groups operated more effective and were more common. Free-lance headhunters were rare, but they did exist, especially among the Iban. A big attack usually was a big social event in which the entire village or several allied villages participated.