Puzzle Ball foraging device for laboratory monkeys (2001)

Crockett, C. M., Bellanca, R. U., Heffernan, K. S. et al.

Abstract

We wanted a foraging device that was inexpensive, durable, and effective, and that could be sanitized during routine cage washing. .. An earlier design of this foraging device was developed by Murchison (1992). The design described here includes modified access holes and a redesigned attachment. .. Puzzle Balls are attached outside of the cage. .. Each animal was observed for 10 minutes after six pieces of cereal were placed in the ball. .. Overall, the subjects manipulated the Puzzle Ball during 69.5% of the scan samples. These observations alsoverified that the animals rarely manipulated the self-locking nut and were not able to remove it. Four of the seven subjectswere able to successfully empty (eat plus spill) at least one type of Puzzle Ball in less than 10 minutes. (Most spilled about asmuch as they ate.) For the successful animals, it took an average of five minutes to empty the puzzle. ...Even though the Puzzle Balls were empty during observations [four of seven cases], the subjects manipulate them, although an average of only 1.6% of the time. During the same observations (Puzzle Ball present), the subjects manipulated their portable cage toys (at least one per cage) an average of only 0.9% of the time. (Eight of 17 manipulated neither Puzzle nor toy.) .. We were pleased that the empty Puzzle Balls were associated with a reduction [approximately 60%] in abnormal behavior.