fully paired or incorporated into social groups (see also Coe 1991). It might therefore be more humane to house some animals alone; these animals could find a solitary life less stressful. The forced pairing or grouping of every primate is not recommended.
Sanitation must be provided, but the procedures used to accomplish good sanitation depend on cage type and species. Sanitation, as used in this report, indicates the maintenance of conditions conducive to health and involves bedding changes, cleaning, and disinfection. Cleaning removes excessive amounts of dirt and debris, and disinfection reduces or eliminates unacceptable concentrations of microorganisms (NRC 1996, p. 42). Portable cages can be taken to a mechanical cage-washer, but built-in cages require hand washing with either brushes or high-pressure sprayers. Corrals might require spot cleaning of feces if heavily populated; otherwise, the sun should desiccate the waste products sufficiently. Wooden structures, such as perches and tree limbs, introduced into a cage need to be replaced as they become worn. Primates have a tendency to lick cage surfaces; therefore, a clean-water rinse should be used to ensure that no trace of detergents or disinfectants remains on these surfaces. Enrichment devices should be sanitized or replaced as appropriate (Bayne and others 1993a; NRC 1996).
When primates are housed outdoors, vermin control in the area is essential. Wild rodents can transmit diseases, and wild animals have been known to attack primates. The ground inside corrals should be graded to permit rainwater runoff and steps should be taken to prevent the formation of stagnant pools of water, such as placing gravel or concrete under waterers. Continuously running streams of water might provide not only drinking water but enrichment, inasmuch as some species enjoy playing in water.
Cage cleaners should always be mindful of the important role of pheromonal communication, especially for callitrichids and prosimians (Epple 1986; Epple and others 1993). Complete sanitizing of a cage can be undesirable for species in which chemical communication is important. At the very least, a few perches or a nest box should be left with odors intact when cages are cleaned. These items should be cleaned at times other than when the entire cage is to be cleaned. Because of the strong role of scents in the lives of many nonhuman primates, one should not be overconcerned about the elimination of odors in a primate room but regular cleaning of surfaces contaminated with urine and feces should be maintained.
The daily observation of all primates in a colony is an important part of a program to provide animal well-being. Caregivers should note deviations from