Of Aristotle's five senses, we know that sight, smell and much of taste are initiated by ligands binding to G-protein-coupled receptors; however, the mechanical sensations of touch and hearing remain without a clear understanding of their molecular basis. Recently, the relevant force-transducing molecules--the mechanosensitive ion channels--have been identified. Such channel proteins purified from bacteria sense forces from the lipid bilayer in the absence of other proteins. Recent evidence has shown that lipids are also intimately involved in opening and closing the mechanosensitive channels of fungal, plant and animal species.