Decision‐making and Anticipation in Pill Bugs (Armadillidium vulgare) Available to Purchase

In the previous study, decision‐making of the direction of motion was found in pill bugs. In the present experiment, we find that they autonomously choose specific places for the decision‐making. Each individual was placed in a circle track surrounded by water. Small columnar marks were placed in the center of the track at equal intervals. At first, when they encountered the marks, they moved along and passed it. After some minutes, they tended to mount on the top of the marks, stayed for a while and swung the antennae as if they searched for the direction of motion. As time went on, they sometimes traced several marks. It seemed that they anticipated the appearance of the mark in advance to use it for decision‐making of the direction of the next motion. In another circle track surrounded by wall, such behaviors were not observed.