Bombardier Beetle

How does a bombardier beetle survive for up to two hours in the stomach of a toad, bathed in harsh tummy acid? No one really knows. How do scientists know that this beetle can survive for so long in a toad's tummy? They watched, as toads, with a lightning-fast flick of their tongue, instantly swallowed a beetle. Then, within a few minutes or even up to a couple of hours later, the toad barfed up the beetle—coated in stomach slime—which slowly crawled away. The dazed-looking toads showed no interest in trying to gulp the beetle a second time.

How does the bombardier beetle accomplish such a Jonah-in-the-whale's-stomach feat? It doesn't need God to order the toad to barf up the little beetle, as he did the whale to liberate Jonah. The bug mixes two chemicals in its butt—hydrogen peroxide and hydroquinone (a derivative of benzene). When these chemicals come in contact, they create an explosion of hot gas that blows out the beetle's butt. The nasty projectile either fends off predators or stuns prey. It's even able to swivel a nozzle on its tail end, to spray the hot fuel in different directions.

Hydrogen peroxide, besides being a sterilizer, can also be used as rocket fuel. It powered the German V1 rocket in WWII. There is no evidence to suggest that the Germans learned this trick from the bombardier beetle. It seems to have been their own brand of rocket science.

Beetles are likely the most prolific type of critter on Earth. They are found everywhere and eat most everything. They are a vital part of the ecosystem. As evidence of beetles' profusion, some 25% of all animal life forms are beetles, and they constitute about 40% of all insects. Entomologists don't even know how many species exist—maybe half a million, maybe several million. 

Beetles are a true insect, which means they have two pairs of wings, but their front pair is hardened into stiff wing cases. In order to fly, a beetle lifts those hard wings and then activates its delicate flying wings hidden underneath. It can't take off instantly, as a fly can, so it's rather vulnerable for a moment or two. That moment is plenty of time for the swift tongue of the toad to swoop out and scoop in the bug.

To set up their experiment, Japanese scientists at Kobe University went into the field and captured several species of toads and beetles. A toad and a beetle were then placed in a glass enclosure. Like Romans watching gladiators, the researchers observed, as the toad scarfed up the beetle and then settled down to digest its catch. Some time later, the bombardier beetle went into action—blending its toxic chemicals into miniature rocket fuel. The scientists could sometimes actually hear the explosion coming from inside the toad's belly, followed by a couple of heaves of the toad's tummy, followed by the ejection of the live beetle, which then slowly crawled away. Just another amazing discovery in the annals of science.