A total eclipse of the sun is a very rare event for a given geographical location, and it is not easy to predict the reaction of animals to such events. On 11 August 1999, the reaction of some species of Saltatoria was quantitatively analysed in a long-term study area for which the normal diurnal song patterns are well established. The song activity of the grasshoppers and bushcrickets declined slowly during the partial eclipse, and stopped completely during the 2-min total eclipse. After a marked delay, song activity returned suddenly to normal. This suggests that light intensity is the main parameter controlling the diurnal song pattern in the species studied, and obviously overrides any internal rhythm.