Communication of information using chemical signals is one of the most widespread and primitive methods of information transfer. Since it is found in plant, animal and microbial kingdoms, it should have been no surprise that fish receiving a dose of ionising radiation, communicate a chemical message to other fish, causing the partner or 'bystander' fish to induce what may be protective strategies, should they be exposed. However, it was a surprise in the radiobiology bystander field and has led to an interesting cross fertilisation between the fields of radiobiology and chemical ecology.