The red and black color of the firebug is made up by pteridines and melanin, respectively. The firebug, as many other heteropteran species [‘true bugs’], are considered to be *aposematic both as larvae and adults.
[*Aposematic species have colors and/or patterns that act as a warning to predators that a potential prey species is unpalatable, toxic or dangerous.]
The firebug combines its conspicuous red and black color pattern with a chemical defense involving over 40 identified compounds. Studies have also shown that birds reject firebugs when presented to them.