In a flock of 3500 modern laying hens with males present at an average ratio of 1:190 females and a density of 7 birds/m 2, male dominance, space use and eventual female attachment were studied by direct observations of the males and a total of 232 female focal birds. Territorial, sexual and agonistic behaviours were observed, as well as the location of the birds during daytime and night roosts. A rank order was determined based on crowings and matings and it was found that high-ranking males used more of the space available than low-ranking males ( P<0.05) and there was a positive correlation between male rank order and space use ( r=0.851, P<0.01). However, most males used more than half of the area. The dominance hierarchy was maintained mainly by low-ranking males avoiding the higher-ranking ones. Furthermore, there appeared to be no strong female attachment to specific males.