How Do Bombardier Beetles Defend Themselves?

The bombardier beetle’s defense mechanism is is one of the most unique and studied in the animal kingdom. It is so incredible that even the origin of its name is derived from it.

The bombardier beetle has two separate chambers a reservoirs located side-by-side in its thorax, or rear of its body. One chamber stores hydrogen peroxide and the other chemical compounds called hydroquinones.

When threatened, these two chemicals are mixed in a third chamber that has a very thick lining in order to protect its body from the explosive chemical reactions that are about to take place there.

The third chamber secretes enzymes which break down the hydroquinones and hydrogen peroxide, causing an intense reaction that releases much energy in the form of heat and pressure.

The sphincter, or opening to the chamber, contracts during this process in order to protect the bombardier beetle’s internal organs from being exposed to the noxious liquid.

The mixture in the third chamber reaches nearly the boiling point of water in a fraction of a second, and is sprayed in a sort of cannon fire up to 20 times in succession before being depleted. It can discharge about six shots in one second.

The bombardier beetle faces its rear towards its target prior to ejection. Depending upon the species, the bombardier beetle can rotate its gland up to 270° in order to properly aim at its target. It usually will only use this extreme defense if it is physically touched by another animal.

The liquid ejection is boiling hot, very foul-smelling, and toxic. If it comes in contact with a small animal or another insect, it can easily kill or injure it. It burns the skin and is quite irritating to human flesh.

As you can imagine, this amazing defense mechanism is quite a deterrent to would-be predators. Most animals quickly learn that bombardier beetles are not to be messed with and are not a potential meal. It is been documented that other species are avoidant of bombardier beetles after interacting with them.

The defense mechanism of the bombardier beetle is so effective that other insects have evolved the ability to mimic it.  The so-called “false bombardier beetle” mimics the appearance of a true bombardier beetle and reaps the reward by being ignored by potential predators.