Flashlight fish have the ability to generate situation-specific blink patterns resembling a visual Morse code. Researchers at Ruhr-Universität Bochum have shown in laboratory and field experiments that the animals use these light signals to coordinate their behaviour in the school when visibility is limited. Both the light intensity and the blinking frequency affected the animals' behaviour. The team has shared their findings in the journal Scientific Reports, published online on 19 March 2021.