Answer:
To you, rude would I never be, Though I flag my tongue for all to see.
Tall when seated, short when standing.
What has armor but is not a knight, snaps but is not a twig, and is always at home even on the move?
My first is twice in apple but not once in tart. My second is in liver but not in heart. My third is in giant and also in ghost. Whole I'm best when I am toast.
It is an insect, and the first part of its name is the name of another insect. What is it?
When someone uses this acronym, you know you've got to pick up the pace