Central-place foraging by Rattus norvegicus on a radial maze.

We studied central-place foraging in rats (Rattus norvegicus) by placing food items that varied in size and weight at the ends of a 4-arm radial maze. In Experiments 1-3, rats increasingly tended to carry food to the center of the maze as the size of those items increased. Very large food items often were hoarded in the center. Rats consumed food faster on the arms than in the center, and rats traveled faster when carrying food than when not. Blocking arm entrances increased travel time between the center and the arms and decreased food carrying at every item weight except the largest. In Experiments 4-6, important conditions that influence the degree of food-carrying behavior were discovered; these were the intersection of maze arms, the presence of a conspecific, and the use of open vs. closed maze arms.