Today I took along a bombardier beetle, Brachinus crepitans, to Ivydale Natural History Club. I’d found it earlier in the day, near Dartford, slightly crushed at the edge of a footpath, but it was still alive and active in a three-legged sort of way. I would try to get it to perform.
In the class I pontificated about cannons, bombardment, chemical explosives and the useful deterent of being able to secrete stable neutral chemicals from abdominal glands, mix them inside a reinforced internal crucible reaction chamber, and then squirting a directable jet of boiling hot hydroquinones into the face of your would-be attacker. There were a few skeptical looks, and maybe 2 seconds before one quipped: “What, it farts?”
I had their attention now; getting them to quiet down to listen took a bit of time. Of course the beetle gets its name from the audible pop of its defensive mechanism. But at only 7 or 8 mm long, even the beetle’s loudest output would need complete silence in the group of 20 giggling 8- to 10-year-olds.
I waited, whilst the beetle shuffled about in its tissue-lined pot, and the general hubbub subsided to calm expectation. Using some fine watch-maker’s tweezers I gently tweaked its back leg and there came the report. The looks on the assembled faces were priceless. Not a pop, not a bang, not a fizz, but a tiny, clear, slightly musical ‘toot’. Perfect.