buried along the perimeter of the cage, approximately 0.5 cm below the bedding so that it was not visible. A mouse was then placed in the center of the cage and the latency to dig up was measured using a stopwatch. If an animal did not locate the odor within 5 min, then the animal was removed, returned to its home cage, and given a score of 5 min. After the trial, each animal was returned to its home cage, and one piece of Purina chow was given. The bedding was changed between mice for all testing periods, and the cereal was buried in a different location on each test day. The surface target test was set up in a similar way, except that on the first day of testing the piece of Purina chow was placed on top of a Petri dish with a cotton ball soaked in 20% ethanol and on the second day the piece of Purina chow was placed on top of a Petri dish without ethanol. After the second day of surface target testing, the buried-target test was performed again daily for three more days. Every day, animals had to find the buried Petri dish
