Slitherine

What on earth do the british mean by the expression "pit ponies" ?

Bugs of some kind?

At first I thought of the lice we call "crabs" or "crotch crickets", but that didn't seem to fit the context.

(Vile, disgusting thought, eh?)

a pit pony is a real pony that was used to work in mines.

if there is some other meaning i dont know though...