Abstract: This study focuses on maternal activities involved in the trapping of piglets by the sow's body in outdoor farrowing systems and examine the mother-piglet context leading either to the death of piglets or to their survival. The behaviour of six Large-WhitexLandrace sows and their litters was continuously video recorded at their first and second parity, during the 40 h following parturition. Crushing mainly occurred at evening and night, during the first 12 h of farrowing and involved changes between lying, sitting and standing positions, as well as between udder and side lying. No piglet died from savaging. Nevertheless, aggressive behaviours of sows were observed, particularly in their first maternal experience. The immediate context of trapping was related to the labour of the sow and to the feeding and resting of piglets. The immediate crushing context was related to active avoidance of restless piglets while lying down, as well as sitting and standing behaviours. These results are discussed in terms of differential reactions of the sow to suckling attempts of piglets.