Galef Jr., B. G., Durlach, P. 1993. Should large rats be housed in large cages? An empirical issue. Canadian Psychology 34, 203-207.

In the present experiment, eight large rats (489-623 g) were each allowed to choose for 24 hr between a 16.8-cm-high [barren] cage and a 23-cm-high [barren] cage. The rats failed to exhibit any preference for the higher cage. It is suggested that before the CCAC mandates commitment of substantial resources for a change in the conditions of laboratory animal maintenance, some objective evidence should be provided that the proposed change improves well being of animals. .. In the absence of such evidence, allocation of hundreds of thousands or millions of dollars to increase the height of rats' cages across Canada is difficult to justify.