This large and impressive insect is widespread throughout the UK, and is found in many diverse habitats including Gardens. They can be easily told by their habit of flashing a reddish patch found on the hindwing when it feels threatened.
The females are larger than the males and have a more rounded abdomen. Moths are regular seen at light, including on occasion, lighted windows! At rest, they tend to sit hanging down amidst leaves, where there coloration and wing shape make them very difficult to locate.