Evaluation of stainless steel reflective discs as enrichment devices for rhesus monkeys (Macaca mulatta) housed in a toxicological facility (1998)

Goode, T. L., McPherson, H., Hughes, J. et al.

Abstract

The enrichment device was used [probably by single-caged subjects] primarily for manipulation and banging. ... The usage of polished stainless steel discs declines over time and therefore alternative methods of environmental enrichment and rotation of enrichment devices should be considered.