A butterfly drinks liquid food through a long coiled proboscis with a pressure gradient induced by a cibarial pump. However, the long and coiled proboscis make it difficult to position the proboscis tip at the liquid target. In addition, the flow resistance in the slender tube is very high. To compensate for these disadvantages, the butterfly proboscis possesses line sink which makes liquid probing easy. In addition, dynamic motions of the butterfly pump exhibit large stroke volume to adapt high flow resistance in the long proboscis.