“What did the rabbit say to the carrot?”/“It’s been nice gnawing you.”

“It’s been nice gnawing you” (a pun on “knowing”) has been cited in print since at least 1950. It’s frequently made into a rabbit riddle:
   
Q: What did the rabbit say to the carrot?
A: “It’s been nice gnawing you!”
 
The riddle was posted on the newsgroup alt.support.depression.manic on December 9, 2002 and is often told at Easter, along with Easter bunny jokes.
 
   
20 April 1950, Philadelphia (PA) Inquirer, “Gossip of the Nation” by Walter Winchell, pg. 21, col. 4:
Sallies In Our Alley: Kaye Ballard, the comedienne, corned a colyumnist and chewed off his good ear for half an hour…She finally landed in his colyum with: “Well, it’s been nice gnawing you!”
 
Google Groups: alt.support.depression.manic
Bunny Jokes
11D Meow!
12/9/02
(...)
Q: What did the rabbit say to the carrot?
A: Its been nice gnawing you.
 
Google Groups: alt.humor.puns
Puns of the Weak 03-14-03
Stan Kegel
3/15/03
(...)
What did the beaver say to the tree?
It’s been nice gnawing you! (Crazy Puns)
 
12 April 2003, Daily Press (Timmons, ON), “Easter Internet style: The good, the bad and the corny” by Steve Elliott, pg. 21:
Q. How do rabbits say good-bye to carrots? A. It’s been nice gnawing you!
 
Southern Maryland Online
101 Easter jokes
jazz lady
04-08-2004, 01:40 PM #1
(...)
Q: What did the rabbit say to the carrot?
A: It’s been nice gnawing at you.
 
Google Books
Grin & Share It!:
More Laugh Lines for Educators
By Diane Hodges
Thousand Oaks, CA: Corwin Press
2008
Pg. 76:
Q: What did the rabbit say to the carrot?
A: It’s been nice gnawing you!
   
Twitter
Diana Adams‏
@adamsconsulting
RT @wbaustin: Q: What did the rabbit say to the carrot? A: It’s been nice gnawing you. Easter Jokes: http://tinyurl.com/cxb7kc
11:28 AM - 29 Mar 2009
 
Google Books
Easter Bunny Jokes For Kids
By Peter Crumpton
PeteyRF Creative
2015
Pg. ?:
What did the rabbit say to the carrot?
It’s been nice gnawing you!
 
Google Books
Katie Woo’s Hilarious Holiday Jokes
By Fran Manushkin
North Mankato, MN: Picture Window Books, an imprint of Capstone Press
2017
Pg. 9:
What did the rabbit say to the carrot?
“It’s been nice GNAWING you!”