Just stumbled onto this thread yesterday... I remember this song from an old 45 when I was a wee thing. (But it was the American version, with Baseball Bat instead of Cricket Bat. Other than that, it was just like Sinsull's version (and the site in her sources link seems to be down).

Anyway, I was wondering:

For those of you who remember the song, what do/did you imagine "They" look like?

...As a kid, I always imagined that they looked a bit like the Shmoo, of L'il Abner, but fuzzy, and brightly colored, like a Muppet.

... I also wonder if they were the inspiration for the Tribble of Star Trek.