Rearing houses for broiler poultry breeders are relatively barren buildings which provide for the basic environmental comfort and nutritional needs of the birds, but offer little in the way of additional novel stimuli (FAWC, 1998). The Farm Animal Welfare Council (FAWC) recommends that environmental enrichment should be available in rearing houses. The Peckablock is a cereal-based enrichment device which is suspended in front of broiler breeders and provides birds with a novel material at which to peck, mimicking their natural behaviour. The manufacturers claim that this stimulus, plus the reward of cereal grains that are loosened and have fallen into the undertray, can help to ameliorate the potential problem of cannibalism. The aim of this study was to investigate the effect of providing Peckablocks on the behaviour and performance of commercial broiler chicks at two different levels of light intensity.