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Small mammals locate buried wet seeds more efficiently than buried dry seeds. This may be attributable to emission of volatile compounds by the seeds. To test this hypothesis I measured emission of volatile compounds from seeds of three plant species (Pinus contorta, Purshia tridentata and Achnatherum hymenoides) under wet and dry conditions using solid phase micro-extraction, gas chromatography/mass spectrometry headspace analysis. Seeds responded in two ways: (1) wet seeds released different, generally greater, amounts of volatile gas than dry seeds and (2) wet seeds and dry seeds released different compounds. Pinus contorta seeds release greater amounts of three compounds when wet: Purshia tridentata seeds release two compounds when dry that are not released when wet, and release increased amounts of two compounds when wet, and increased amounts of two compounds when dry; Achnatherum hymenoides releases at least 22 compounds, one of which is released in large concentrations when wet. These data suggested two mechanisms by which small mammals locate buried seeds. First, small mammals may be sensitive to release of differing concentrations of volatile compounds by seeds. Second, small mammals may be sensitive to compounds released by wet seeds that are not released by dry seeds. Ability of seeds to survive depredation by granivores may be an adaptive trait influenced by natural selection.