Trying to identify book(s) with 'Gnomes' that moved too fast to be seen

As a kid I read these stories about these "gnome" men who moved too fast to be seen by normal people (sometimes they'd see a blur). Because they lived so fast they only lived like 3 days but that was years to them. I believe "gnome" had alternative spelling too, because somehow they were different.

I remember in one of the books they had to stand really still to get a humans attention and talked about tying his shoes to trip him when he was sleeping. It also mentioned when things go missing or get moved it's them.

I really want to find the book again but all I can find is that Gnomes book that's a bit different. I remember reading novels and I am pretty sure it didn't have full colour pictures.

Please help!