“Why do hens lay eggs?”/“Because if they dropped them they’d break.”

A popular riddle about eggs has been cited in print since at least 1893:
 
Q: Why do hens lay eggs?
A: Because if they dropped them they would break.
 
A Thanksgiving version of the riddle involving turkeys was posted to Twitter on November 22, 2012:
 
“Why do turkeys lay eggs? #iftheydroppedthemtheydbreak.”
 
   
Chronicling America
9 February 1870, Urbana (OH) Union, “Chips and Splinters,” pg. 3, col. 6:
Not having heard from the debating societies in relation to the conundrum, “Why do hens lay eggs in the day time?” a contemporary answers, “Because at night they are roosters.”
 
12 April 1893, Riverside (CA) Daily Press, “Local News,” pg. 3, col. 2:
As long as O. A. Smith remains in town it is necessary to look out for jokes. He fired the following conundrum at us today: “Why do hens lay eggs?” being naturally dull witted, we gave up. The answer is, “Because if they dropped them they would break.”
 
Chronicling America
24 July 1900, Santa Fe (NM) New Mexican, pg. 3, col. 3:
Sure Enough.
Little Clarence—Pa, is there a reason for all things?
Mr. Callipers—Yes, I suppose so.
Little Clarence—Well then, pay, why do hens lay eggs?
Mr. Callipers—Because they can’t stand them on end, my son.—Judge.
 
25 February 1959, Rochester (NY) Democrat and Chronicle, “Fun Time—The Riddle Box,” pg. 13, col. 5:
Why do hens lay eggs?
If they dropped them they would break.
 
26 September 1961, San Diego (CA) Union, “Fun Time—The Riddle Box,” pg. A9, col. 2:
Why does a hen lay eggs?
Because if she dropped them they’d break.
 
Google Books
696 Silly School Jokes & Riddles
By Joseph Rosenbloom
Illustrated by Dennis Kendrick
New York, NY: Sterling Publishing Company, Inc.
2003
Pg. 32:
TEACHER: Why do chickens lay eggs?
RAMONA: Because if they dropped them, they would break.
 
Google Books
A Prairie Home Companion
Pretty Good Joke Book (5th Edition)
Introduced by Garrison Keillor
Miineapolis, MN: HighBridge Company
2009
Pg. ?:
Why do hens lay eggs?
If they dropped them, they’d break.
 
Twitter
nicole murawski
‏@nmurawski
Why do turkeys lay eggs? #iftheydroppedthemtheydbreak
3:55 PM - 22 Nov 2012
 
Twitter
Joey Little
‏@SocialLittleMan
Why do turkeys lay eggs? (If they dropped them, they’d break!) @HappyThanksgiving
6:24 PM - 28 Nov 2013
 
Google Books
Thanksgiving Turkey Jokes For Kids
By Peter Crumpton
PeteyRF Creative
2015
Pg. ?:
Why do turkeys lay eggs?
If they dropped them, they’d break!