The Bombardier beetles are a type of ground beetles(Carabidae).They make up the tribes Metriini, Brachinini, Ozaenini, or Paussini.There are currently more than 500 species altogether. The bombardier bettle inhabits all continents, except Antarctica, and they basically feed on smaller insects.There is actually something unique about these beetles, which is one of the reasons they were named the bombardier beetles. These beettles have an amazing defense mechanism. When they are threatend, they release a toxic chemical spray from the tip of thier abdomen, while making a pop sound. So if you come in contact with a bombardier beetle, all you’ll hear is pop, while you’re splashed with hot boiling chemical spray, That’s nasty!A reaction between hydroquinone and hydrogen peroxide produces the toxic spray.(The end product of the reaction is called benzoquinone). Reservoirs in the beetles abdomen, stores the two chemical compounds. There are two large glands that open at the tip of the abdomen. Each gland has a composition of a thick walled vestibule. The vestible contains a mixture of catalases and peroxidases which is produced by the secretory cells lining the vestibule. An aqueous solution of hydroquinones and hydrogen peroxide contained by a thin-walled and compressible reservoir makes up both glands. There is no reaction between the two chemical compounds in the reservoir because there isn’t enough energy to enable the reaction.Image SourceImmediately the solution of hydroquinone and hydrogen peroxide reaches the vestibule, the catalases and peroxidases in the vestible will enhance the decomposition of the hydrogen peroxide and the oxidation of the hydroquinone.The mixture is shot to almost the boiling point of water by the heat produced from the reaction, thereby producing gas which drives the ejection. The damage this spray causes can be fatal to insects that are sprayed. Some bombardier beetles can shoot the spray a bit further and wider than others. The benzoquinone spray is quite potent as it can burn an adult human’s skin and leave a mark that lasts up to 3 weeks.