Brachinini
Paussini
Ozaenini
Metriini Bombardier beetles are ground beetles (Carabidae) in the tribes Brachinini , Paussini , Ozaenini , or Metriini - more than 500 species altogether - that are most notable for the defense mechanism that gives them their name: They can fire a mixture of chemicals from special glands in their posterior. There are three chambers in their abdomen, two of which contain liquids that are chemically stable in isolation but react violently when mixed. The third chamber is a reaction chamber into which the two chemicals are squeezed when danger is near, and from which they are expelled explosively towards the perceived danger.

Bombardier beetles have come to public attention in recent years largely because of arguments put forward by creationists, particularly in the children's book Bomby the Bombardier Beetle. The book argues that the beetles' internal design, in which certain chemicals must be mixed in certain ways at certain times to produce tiny explosions, is an example of irreducible complexity, and therefore the product of intelligent design.

However, some researchers have shown that their chemical weapon is only minor alterations of other less noxious beetles.

Further reading

• Bomby the Bombardier Beetle, by Hazel Rue, ISBN 0932766137

External links

• Bombardier Beetles and the Argument of Design, from the the talk.origins archive
• Proceedings of the National Academy of Sciences article: "Spray aiming in the bombardier beetle: Photographic evidence"