Cardinal beetles prey on other insects, while their bright red colour prevents them being the target of other predators which believe them to be toxic. The red-headed or 'common' cardinal beetle (Pyrochroa serraticornis) is a red to orange beetle with, as the name suggests, a red head. It is found throughout Britain. The rarer black-headed cardinal beetle (Pyrochroa coccinea), similarly found at sites across Britain, is larger and a deeper blood red.