The choice of floor type is also very important. You can use a drop tray, peat, sawdust, straw, dried leaves or wood chip floors for smaller cages. Larger cages are probably better off with cement floors, floors covered with linoleum, kitchen or bathroom floors. This will also prevent a monkey from reaching for food or other items fallen onto the soil. Use branches from for instance salix, pseudoacacia or sambuncus trees.
Natural gum is very rich in vitamin D and Calcium and therefore recommended for most primates.
However beware in spring when the gum is young, it may cause intestine problems.