Losing My Knack

Missing: one knack.
You must have seen it! I don't doubt it-
So please return it hurriedly,
For I cannot do without it.

I've looked on each shelf, and under my bed,
I've poked into crannies and nooks,
But my knack isn't there! And it's really not fair
To dredge out ideas from my books.

It's about this big, and about this high,
And it likes to squeak and scurry.
Don't alarm yourself, dear reader,
But I'm really in a hurry

To regain my little writing bug
My critic and my friend,
Who cheeps ideas into my ears-
Else my writing days must end.

What kind of creature nicks a knack?
I simply fail to see.
Please, if you're a writer, you'll understand.
Please bring back my knack to me.