There is some evidence that rats benefit from social housing and from some forms of environmental enrichment, such as platforms and shelters. It is less clear whether they benefit from more spacious cages. There is a lack of information about the relative benefits of social contact, enrichment and increased space, because existing studies tend to concentrate on only one of these variables at a time. The current experiment used economic demand procedures as a method to compare, on a single scale, qualitatively different environments with a standard home cage. The data indicate that rats show a high demand for social contact, and a low demand for a larger cage or one containing pillars or novel objects. This finding suggests that social housing of laboratory rats should be strongly advocated.
