Small fly with illuminated abdomen

Small fly with illuminated abdomen

Observation - Small fly with illuminated abdomen - UK and Ireland. Description: This small fly was spotted as its rear end appeared to be lighting up in flight. This appeared to be the males lighting up when flying around the females (my assumption).

This small fly was spotted as its rear end appeared to be lighting up in flight. This appeared to be the males lighting up when flying around the females (my assumption).