As revealed in Table 3, there was a significant difference ( p < 0.001) in tonic immobility duration between the LED and ICD groups. The duration of tonic immobility, a response which increases with fearfulness, was much longer in chicks reared LED light. On the other hand, chicks reared under ICD light showed lower tonic immobility, means that ICD light reared chicks were less fearful than LED chicks. Therefore, it suggests that LED light would increase the fear responses of chicks.