Bombardier Beetles' Defense:
by Design or Chance

All bombardier beetles can emit an explosive chemical spray from the tip of their abdomen. They are found on all continents, except Antarctica. Of the hundreds of bombardier beetle species worldwide, about 48 are found in the North American continent.


African bombardier beetles, Stenaptinus insignis, have been extensively studied by scientists for many years because of their highly effective chemical defense system. They are capable of explosively spraying a hot caustic fluid from the tip of their abdomen against potential predators, such as spiders, ants, frogs, and birds. [1] Temperature of this spray at 100 0C or more is a significant deterrent by itself. [2][3] These beetles can accurately target predators in virtually any direction, even over their heads. [4][5] Spray range is a remarkable 20 to 30 cm for the small size of their combustion chambers. [6] “A single bombardier beetle can discharge upward of 20 times before depleting its glands.” [7] Each discharge is accompanied by an audible pop.


This system has all the hallmarks of being designed. Like any design, it starts with a purpose. The purpose of this design is to protect the beetle. Then, there Is the plan to accomplish this. Individual components need to be envisioned and design problems worked out. Assembly instructions need to be put in place so that all parts are right fitting and working together properly. The right materials need to be available where and when needed. Assemblers need to be present to follow the assembly instructions.

Now let’s look at the defense system’s parts and purposes.


a.    Sensory (eyes, antennas, and nerves) - to sense and transmit information to brain.

b.   Brain - to process information using complex algorithms to determine danger and direct response.

c.    Nerves - to send signals from brain to start defense if in danger and to direct spray.


The portion of the defense system outlined below has two separate tracks with identical components. [8] The descriptions below apply to the components in each tract in order from making the reactants to exhausting their products of combustion. 


d.    Secretory lobes - to synthesize the two reactants, hydroquinone, and hydrogen peroxide in aquas solution for chemical defense. [9]

e.    Collection tubes from the secretory lobes - to collect the synthesized aquas reactants and deliver them to the main tube. [10]

f.     Main tube – to transport the reactants to the reservoir. [11]

g.    Reservoir – to store the reactants for use as needed. [12]

h.   Striated muscle surrounding the reservoir - to apply pressure to force the reactants from the reservoir when it receives a signal from brain. [13]

i.      Thin tube from the reservoir - to transport the reactants to the combustion chamber.[14][15]

j.      Valve in latter tube – to control flow from the reservoir to the combustion chamber. [16][17] This valve initially opens under pressure from the squeezed fluid in the reservoir. Then it closes from the pressure generated from the exothermal reaction in the combustion chamber that causes the portion of the chamber surrounding the tube to expand pinching off the tube. When the fluid in the chamber is expelled, this valve then reopens under pressure from the reservoir fluid. This allows more reactants from the reservoir to enter the chamber starting the cycle over again. [18][19] And, this cycling proceeds very rapidly until the muscle surrounding the reservoir is relaxed or the reservoir is empty.

k.    Lobes - to manufacture two catalysts, catalase, and peroxidase, needed for the chemical reaction in the combustion chamber to proceed. Some researchers place these lobes on the combustion chamber walls and other researchers did not find them there. [20]

l.      Combustion chamber – to provide a suitable place for the exothermic reaction involving the reactants and catalysts. This reaction rapidly proceeds producing a boiling solution of benzoquinone and water accompanied with high pressure to explosively exhaust the hot solution. [21] The combustion chamber is possibly lined with special material to resist the heat generated. [22]

m.  Exhaust tube – to exhaust the fluid from the combustion chamber to the exhaust turret and deflector plate(s). [23][24]

n.    Exhaust valve – to allow the pressure to build up in the combustion chamber to greatly increase the exhaust pressure and velocity. This valve is forced open when sufficient pressure is built up in the combustion chamber and closes when the chamber’s contents are expelled. [25]

o.    Exhaust turret – to direct the exhaust fluid with pinpoint accurately at the predator based on impulses from the brain. The beetle can move the turret in almost any direction even twisting to direct the spray over its back towards its front. [26][27][28]

p.   Deflector (reflector) plate(s) – to work together with the exhaust turret to “give directional control to the discharge by changing their angle of deflection.” [29] “Deployment of the reflectors would appear to require special action on the part of the beetle.”[30]


The bombardier beetle’s system of defense utilizes a “sophisticated and specialized biological design” that “works to simultaneously achieve defensive and protective functions.” [31] How its internal organs are protected is not fully understood. But like airplanes, cars and computers, all complex design requires an intelligent designer.

“Evolutionists state that the bombardier beetle’s chambers evolved from minor structures through mutations and survival of the fittest to become the insect’s primary defense mechanism.” [32]



(a)  Bombardier Beetle from India, L. Shyamal, Public domain, via Wikimedia Commons




[1] McIntosh, A.C., and Lawrence, J., The extraordinary design of the bombardier beetle- A classic example of biometrics. In Proceedings of the Eighth International Conference on Creationism, Vol. 8, ed. Whitmore, J.H., (Pittsburgh, Pennsylvania: Creation Science Fellowship, 2018), 268-276

[2] Armitage, M., and Mullisen, L., Preliminary Observations of the Pygidial Gland of the Bombardier Beetle, Brachinus sp., Journal of Creation 17, (1), April 2003, 95-102

[3] Eisner, T., Aneshansley, D.J., Spray aiming in the bombardier beetle: Photographic evidence, PNAS, 96 (17), August 17, 1999, 9705-9709

[4] McIntosh, A., The Amazing Bombardier Beetle, Creation 42(2): 12-15, April 2020

[5] Armitage

[6] McIntosh, A.C., and Lawrence, J.

[7] Eisner

[8] Armitage

[9] Ibid.

[10] Ibid.

[11] Ibid.

[12] Ibid.

[13] Ibid.

[14] McIntosh, A.

[15] McIntosh, A.C., and Lawrence, J.

[16] Ibid.

[17] Armitage

[18] McIntosh, A.

[19] Armitage

[20] Ibid.

[21] McIntosh, A.C., and Lawrence, J.

[22] McIntosh, A.

[23] Ibid.

[24] Armitage

[25] McIntosh, A.C., and Lawrence, J.

[26] McIntosh, A.

[27] McIntosh, A.C., and Lawrence, J.

[28] Armitage

[29] Ibid.

[30] Eisner, T., Aneshansley

[31] Chandler, D, How some beetles produce a scalding defensive spray, MIT News Office, April 30, 2015

[32] Bombardier beetle, CreationWiki, viewed February 4, 2022




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