Two groups of day-old domestic chicks were exposed to constant white light for one hour. Chicks in one group were socially isolated but unrestrained; the others were unable to move their heads. Later the accuracy of their pecking at millet seed was compared with chicks kept in the dark up to the time of testing. The unrestrained chicks exposed to light were markedly more accurate than the dark-reared birds. The restrained chicks were intermediate in performance between the other two groups hitting seeds more frequently than the dark group but missing more and picking up and swallowing less than the unrestrained Light group. The effects of light on pecking accuracy are interpreted primarily in terms of non-specific stimulation of the visual pathways.