Ferraro, A. S. 2013. Stainless steel puzzle feeder. Enrichment Record 17, 5-6.

This NHP puzzle feeder was designed and manufactured with the assistance of a local metal fabricating company. The need for a custom feeder arose following the use of several types of commercially available NHP puzzle feeders, all of which had shortcomings including: lack of complexity, difficulty in filling, difficulty attaching and securing, and difficulty in proper sanitization.We wanted a feeder that could be easily and securely attached to the front of our cages and that would be sanitizable and able to be run through our cage washer with the entire cage.These puzzle feeders meet all of the needs that they were designed to address. They are easy to fill with biscuits, only taking a few seconds per animal and requiring most animals to take 20 minutes to successfully retrieve their biscuits. They are a great form of occupational enrichment, making the animals work for their food. They stimulate the animals natural desire to forage while utilizing their standard food portions. We have been using these feeders continually for the past three years; so far there have not been any issues with durability. One of the cons with this device was the initial investment; each feeder cost $380. This may seem excessive, but, due to their durability, we don't foresee any need for replacements in the near future. Another issue is the weight of the feeder; each one is close to 10 pounds, making them somewhat difficult to move around the facility and attach to the cages. Also, although they do a good job of making the animals work for their food, the maze design is identical on all the feeders, and we have noticed that, after several months, some animals learn how to retrieve their biscuits much more quickly, therefore reducing the feeder's value as an enrichment strategy for long-term animal holding. If we were to order more feeders, we could minimize these few issues by using a thinner gauge of steel to help reduce weight as well as cost, and design multiple maze types to increase variability for our animals.