The firebug is 10 to 12 millimetres long and has a flat, oval body with striking red and black colouration.
This beetle lives in deciduous trees, especially old lime trees, in Europe, Asia, the USA and Central America.
Unable to fly, these social beetles live in colonies at the base of lime tree trunks. When mating, the male and female attach themselves to each other by the rumps and walk together, one forwards and one backwards. They feed on the fruit of lime trees, dead insects and grains. Firebugs hibernate in winter.