The objective of this study was to compare thebehaviour of piglets raised in two different rearing envi-ronments. The animals were either removed from the sowat the young age of 3–6 days and raised in a commer-cially available artificial piglet rearing system (group size:7 piglets) or reared by the sow in a loose farrowing pen (7focal piglets observed per litter). The study was conductedon an experimental farm on which we had full control ofthe two different rearing environments and several batchesof animals were included. We specifically expected a highincidence of belly nosing in artificially raised piglets andwere further interested in differences in manipulation ofpen mates, play-fighting, and aggressive as well as restingbehaviour.2.