Coleman, K., Weed, J. L., Schapiro, S. J. 2017. Chapter 2 - Psychological environmental enrichment of animals in research. In: Animal Models for the Study of Human Disease (2nd ed). Conn, P. M, (ed), 47-69. Academic Press, London, UK.

Environmental enrichment is an integral part of animal care practices. Enrichment generally refers to items we provide to the animals to support their behavioral needs. It provides a way to functionally simulate the natural environment of captive animals, in an effort to increase opportunities for the expression of species-specific behaviors and decrease the occurrence of abnormal behaviors. Further, enrichment can also be a tool in the study of basic science questions, such as how environmental factors may affect disease etiology or progression. In this chapter, we discuss enrichment as both a welfare tool and as an experimental model. We will also discuss whether enrichment increases variability in research protocols, and present some practical tips on ways to implement an effective enrichment program for laboratory animals.