nepenthes traps contain a fluid of the plant's own production, which may be watery or syrupy and is used to drown prey. the trapping efficiency of this fluid remains high, even when significantly diluted by water, as inevitably happens in wet conditions. many species of "nepenthes" produce two different forms of pitchers. near the base of the plant are the large lower traps, which usually sit on the ground, while the upper pitchers may be smaller, coloured differently, and have different shapes and features than the lower pitchers.