Who are the Spoonsize Boys ?

“The Spoonsize Boys steal the dollhouse toys/while the cat by the fire is curled. Then away they floats in their eggshell boats/down the drains to their underground world.”

I ran across these lads in a semihistorical-novel (The Anubis Gates, by Powers) and wonder if they are based on “an old English fairytale” as claimed by a google cite, or are instead a product of the author’s imaginings, as is the fictitious poet William Ashbless ?

Can’t speak to the origin, but my first thought upon seeing the thread title was that it’s a euphemism for sperm.

Reading the verse, I still believe it’s a euphemism for sperm.