The seeking of novelty and its relation to play

Abstract Inquisitive exploration, in which an animal acts so as to initiate a change in its environment rather than responding to a stimulus, was studied in six litters of domestic piglets, Sus scrofa, aged 5–6 weeks. During 16 tests each of 5 min the piglets were allowed to enter two side pens adjacent to their home pen and with either a novel or a familiar object hidden in it. No object had any biological value to the piglets, and in each test a different novel object was used. They were placed in the same side pen over all sessions with each litter, and all litters showed a significant preference for the pen with the novel object in it first. Exploration directed towards the novel objects lasted 2·3–92 times, longer than towards the familiar objects. However, the interest in the novel objects declined rapidly and significantly over the 5 min of each session. During the same time, play, i.e. scampering and sparring, increased significantly. The function of this could be to direct the attention of litter-mates towards the novel stimulus and to make them participate in the exploration. The ability of the piglets to learn to enter first the pen with the novel object and consequently to examine it is considered clear evidence for the presence of inquisitive exploration. Therefore pigs seem to possess a high level of curiosity, and the results underline the need to do away with monotonous environments if the welfare of piglets is to be considered seriously.