To be accepted into this elite group, prospective entrants must demonstrate they’ve invented a mousetrap that no one else has thought of. The trap must not kill the mouse, so bringing your hungry pet cat to the entrance exam won’t work. Would-be members have one hour to show their trap will work in an area 16-feet square, inhabited by three mice who have not been starved. Variations on rustling paper and plastic bags in a larger bin bag will no longer be accepted.

Members-only competitions are held every three months, where a prize of 500 pounds will be awarded to the person whose trap catches the most mice in a period of three hours. Mice captured more than four times in any calendar year are deemed to have become institutionalised and will be released back into the wild in a British National Park, normally Snowdonia or the North Yorkshire Moors.

Norman Hillier has won the HUMOTSO prize more than anyone else, although he admits he still hasn’t designed the perfect trap just yet: “The ideal trap would be one that is triggered by the mouse entering the trap, but not being able to leave again. It’s similar to the bird feeders that are squirrel proof and are activated when the squirrel jumps on them, only that in my example the mice would be kept inside rather than kept outside. It’s a tough one to sort out even for someone with a creative mind.”

Extract from the 40 Strange Groups