Experiments on fire manipulation of bones as fuel demonstrated that animal bones are effective in the act of maintaining lasting combustion. These experiments are almost always applied to the studies in hunter–gather societies in prehistory, even though the use of bones as fuel is also known in historical times. Based on data and models resulting from these recent experiments, both in laboratory and in real hearths, I tested the hypothesis of the use of animal bone as fuel in the third/second millennium BC walled enclosure of Castanheiro do Vento, in northern Portugal. The faunal assemblage shows some specific characteristics such as a very low percentage of identifiable material and close to 90% of charred bones with a very high index of fragmentation I link the faunal analysis with the results of some experiments recently published. These experiments show the particularities of bone fuel combustion, specifically used in certain activities. Nevertheless, the interpretation of these activities in Castanheiro do Vento is difficult to achieve because of the preliminary state of the investigations. As an additional problem, the available interpretations in the literature concern mostly hunter–gather, and models do not take into account the complex societies of the third/second millennium BC. Copyright © 2015 John Wiley & Sons, Ltd.