Hatching activity of eggs kept in a group (A–F.) and those kept singly (G–L.) in a thermocycle of 30 (orange) and 25°C (blue) under continuous illumination in the six indicated grasshopper species. The numbers of eggs that hatched over 2–5 days were pooled and plotted against the time of day. Black arrows indicate the medians. Asterisks indicate a significant difference between the two treatments by the Mann Whitney U-test at the 5% level. The photographs on the right show hatchlings of respective species. Scale bars: 5 mm.