This experiment attempted to determine the effect that group size has on feather pecking as well as, examine the relationship between feather pecking and ground pecking in laying hens. The group sizes examined were 15, 30, 60 or 120 hens per group. At four different ages (22, 27, 32, 37 weeks of age) the number of feather pecks and aggressive pecks given and received were recorded. The part of the body that was pecked, the location of the birds within the pen during a pecking incident and the number of pecks directed towards the floor, feeder and drinker were also recorded.