The objective of the present study was to clarify the details of maternal behaviour and the effects of broody hens on the behaviour and character of chicks. Five groups of five chicks each were reared by broody hens and five groups of five chicks were provided with a heater for 28 days. The behaviour of all chicks was recorded using scan sampling at 5 min intervals for 6 h per day at 1, 5, 9, 13, 17, 21, and 25 days of age. Two behavioural tests for evaluation of fearfulness and familiality with humans were conducted, and the number and latency of freezing, vocalizations, and steps taken were recorded for 10 min. The data was analyzed using repeated measure ANOVA or Student's t-test. The chicks spent 60% of their time on brooded behaviour (the state of chicks being brooded by hen) at 1 day of age. The time spent on brooded behaviour decreased sharply during two weeks with development of regulation of body temperature, and then decreased gently. At 25 days of age little brooded behaviour was observed. The brooded chicks spent more time on active behaviour (59.7% vs. 42.8% ; F=10.1, P<0.05), especially dust-bathing(0.8% vs. 0.4%; F=5.9, P<0.05) and floor pecking (43.8% vs.28.4%; F=10.2, P<0.05), but less time on gentle feather pecking (1.0% vs. 1.6%; F=12.1, P<0.01) than non-brooded chicks. In both behavioural tests, the total duration of freezing was shorter in brooded chicks (90.4-167.8 vs. 387.1-467.4 sec.; t=-4.4, P<0.001), and the total numbers of vocalizations (278.0-280.1 vs. 14.9-29.6; t=7.0, P<0.001) and steps (133.5-188.8 vs. 3.6-9.8; t=5.9, P<0.001) taken were greater in brooded chicks. In conclusion, maternal behaviour has a close relation with development of regulation of body temperature, and the development of behaviour of chicks was promoted and fearfulness was decreased remarkably by provision of broody hens.