Cages are regularly disinfected. Of the island colonies, Dao Thi near Nha Trang is the largest at 280 ha., holding 500 M. mulatta, half its capacity. Breeding groups are kept on this island. There was once a hamlet on Dao Thi, but the Company moved people from this island because the animals became pests. As a result, monkeys on this island now forage among the orchards and other crops which include mangoes and coconuts.
Animals can forage for food on the islands, but they are also provisioned.
At Dao Thi, provisioning is at a large feeding area surrounded by a fence to exclude a few buffalo which are also raised on the island. The 18-4 Company lost direction following the collapse of the former Soviet Union. First, it has been impossible to sell animals to Russia. Repeated negotiations with Russian trade representatives have failed. As a result, the Company is over stocked with M. mulatta and it is forced to limit reproduction in this species.