The chicken body louse, Menacanthus cornutus (Menoponidae s.l.) completes its whole life cycle on the body of Gallus gallus domesticus. The louse exploits the microclimate developed by host skin temperature and feather cover. The weekly visual examination has demonstrated the pronounced response on the population fluctuation of M. cornutus to the seasonal changes in the environment despite all favourable condition on the body of homothermic host. The experiments commences from April 2008. The peak index was obtained in the month of August followed by drastically decline in succeeding 5 months. Lice index begins building up slowly from the months of February and March. The correlation between mean monthly lice indices with temperature and photoperiod were analyses as strong positive. The moderate positive correlation was found with relative humidity and it remained insignificant with rainfall.