BUG

Does anyone have any idea what this is please? Not the male thumb, that's for size comparison.

I slid it onto a book cover to move it to a plant but it must have had suckers on its feet as it took a fancy to the book and I could not shift it!

Gardening, reading, when I got the book back, and listening to the cricket today.

Edit: thanks to shielwill and gladders, Crataerina pallida. This site is the fount of all knowledge!