Riviello, M. C., Misiti, A. 1995. An alternative to woodchip as a foraging substrate for tufted capuchin monkeys (Cebus apella). Primate Report 42, 24. (Abstract)

Our laboratory, a short time after the introduction of woodchip, became infested with domestic mice. ... We decided to adequate the original idea changing woodchip with argilla espansa ... a material that is used in gardening to improve the permeability of the soil. It is made of little rocks, light and porous, of different size from 0.5 to 1 cm and it could be comparable with lava rock. The result was excellent. It provided an ideal substrate in which the primates could search for food and mice were no longer attracted to the laboratory. Moreover the argilla espansa is light and therefore easily handled by the monkeys, it is porous and dries in a short time, it does not produce dust.