Knee high

What does "Bow high to a squirrel" mean or "knee high"?

"Knee-high to a squirrel" (or to any other small critter) is a wity way of describing someone of short stature.

Where I come from it used to be "knee high to a grasshopper."
SS

I've never heard "squirrel"; I take "grasshopper" to be the usual form, although I've heard "knee high to a tabletop" from a Scouser (Liverpudlian). (VSD)