Fig. 1.

Foraging experimental design. (A) Baseline days. Snapshots show a rat emerging from a nest into a foraging area to search for pellets placed 25.4, 50.8, and 76.2 cm away. Once the animal returns with the food to the nest, the gateway closed until the next foraging trial. (B) Test day. Snapshots show the same rat foraging for a pellet 76.2 cm from the nest when confronted with a Robogator for the first time. Each time the animal approached the vicinity of the pellet (about ≤25 cm), the Robogator surged, snapped its jaws once, and returned to its original position. The rat immediately fled to the nesting area. A stationary Robogator did not obstruct foraging. (Video clips are available at http://faculty.washington.edu/jeansokk/Robogator.html).