So to battle with my rodent foe. A rule of thumb is if one is caught there are two about, if two are caught in two days there's four etc. So I decided to invest in a humane mouse trap that could catch up to ten at a time. The PoW squeakers could then be released in a nature reserve a mile away or quickly neck-stretched.*
Here's the galvanised metal humane trap with clear plastic panel on the lid and ample ventilation holes. There are two entrances and mice walk up a pivoted flap into the bait area. When they put their feet on the flap to leave its outside end pushes up pushing up a metal door which prevents exit. The trap resets itself.
Don't read below if you don't want to know how to humanely despatch a mouse.
*To do that, quietly calmly quickly pick the mouse up by its tail with one gloved hand and gently grasp the mouse's head with the thumb and forefinger of your other hand, simultaneously pulling down and twisting slightly. The mouse's back legs will judder momentarily but it's already dead. Double-plastic bag it in and bin it straight away.