MIT scientist Eric Arndt and his colleagues have discovered that the superheated mixture comes out of the combustion chamber in a series of pulses rather than a continuous spray. This prevents the beetle's body from overheating while still scalding its would-be predator. See: Arndt, E.M. et al. 2015. "Mechanistic Origins of Bombardier Beetle (Brachinini) Explosion-Induced Defensive Spray Pulsation." Science 348 (6234): 563-567.

Other arthropods also produce some of the same chemicals found in bombardier beetles. Like bombardier beetles, these chemicals are used for defense or make the animal distasteful to predators; however, the mechanisms are not as sophisticated as bombardier beetles. Starting with these simpler mechanisms, a plausible step-by-step microevolutionary pathway culminating in bombardier beetles can be constructed. In fact, Mark Isaak (2003) discusses this in his on-line article entitled: "Bombardier Beetles and the Argument of Design."