Kaplan, M. L. 1993. An enriched environment for the African clawed frog (Xenopus laevis). Lab Animal 22(5), 25-29.

A continuous-flow aquatic housing system for frogs is described. Sandstones and a stainless-steel rabbit feeder were used for enrichment. The animals swam into the feeders immediately, and three of four animals usually occupy each feeder at any given time.