Wolper, C. 1995. A hammock in the rain forest for chimpanzees. The Shape of Enrichment 4(3), 1-2.

Getting the [group-housed] chimps off harsh concrete surfaces and providing them with softer substrates has long been a goal. The hammock has been up for three months now. It gets constant abuse and absorbs it well. Some chimps use the hammock as a transport system to get from one side of the room to the other. It has also become a trampoline and a device for playing hide-and-seek. Some even use it for resting. No data are included in this article.