Joseph Barad and Edward Markoff were certainly humane — the rat trap they patented in 1908 merely fastened a jingling necklace around the animal’s neck and released it.

What would that accomplish? “The ‘bell-rat’ as it may be termed, then in seeking its burrow or colony announces his coming by the sounds emitted by the bells, thereby frightening the other rats and causing them to flee, thus practically exterminating them in a sure and economical manner.”

Did it work? Who knows?