The authors of this study found that light flashes caused rapid contractions of Drosophila melanogaster photoreceptor cells, and that such contractions did not occur in cells from flies lacking phospholipase C (PLC). PLC causes these contractions by hydrolysing the membrane phospholipid phosphatidylinositol 4,5-biphosphate (PIP2) and thereby depleting it from the plasma membrane. The results suggest that these mechanical changes help to gate the light-sensitive channels in these cells.