La Demoiselle Josseline Leloup, infamous lady scientist and toast of the Parisian Société des Explorateurs, was well known for her subtle touch. Never one to design oversized crude contraptions when smaller inventions that tackled a problem from a  different angle would do, she constructed the Mischief Bugs to distract and confuse enemies while she moonlighted as La Chouette, the Owl, a notorious liberator of prisoners.

Mischief bugs are tiny clockwork devices motivated by a series of clever cogs and springs which will gravitate towards load bearing organic material, like straps, linings, wooden poles, ropes, and even shoes. They will chew on and consume this material, feeding the microscopic furnace within them, puffing out occasional tiny wisps of green steam, but won't gnaw all the way through anything, moving on once their meal is half finished.

This has the effect of weakening anything made of animal or vegetable material, often in very tiny ways that won't immediately fail. If set loose on a ship without interruption, one Mischief Bug is capable of making it unseaworthy within a couple of days. Cables snap, crates collapse, sails shred and saddlestraps fail at the most inopportune moments.

They periodically go dormant from time to time, curling up into tiny metal balls and hiding themselves inconspicuously in small cracks or down narrow holes. They won't attack living material, and can only be found by specially trained cats of the Cornish Rex breed, who can hear the clicking and scratching noises they make.

Madame Leloup reputedly has a silver whistle she can use to recall Mischief Bugs within hearing, although it makes no sound audible to human ears.