A riddle about opening a jar is:
 
Q: Why did the little kid dance on the jar of jam?
A: Because the top said, “Twist to open.”
 
A form of the riddle—with an “ant” dancing instead of a “kid”—has been cited in print since at least 1972.
 
“Why did John jump up and down before drinking his juice?”/“The box said “Shake well‘“ and “This orange juice says shake well before drinking…” (drinking alcohol) are “shake well” jokes.
   
 
11 November 1972, Cumberland (MD) Times-News, “Mini Jokes, The Mini Page, pg. 3, col. 1:
Q. Why did the ant dance on the lid of the peanut butter jar?
A. It said twist to open.
(Rhonda Middleton, Cumberland)
 
14 January 1973, Pittsburgh (PA) Press, “Mini Jokes,” The Mini Page, pg. 3, col. 1:
Q. Why did the ant dance on the jar?
A. Because it said: “Twist to open.”
—Robin Marsteller (Monroeville)
 
Google Books
Biggest Riddle Book in the World
By Joseph Rosenbloom
Illustrations by Joyce Behr
New York, NY: Sterling Publishing COmpany, Inc.
1976
Pg. 133:
Why did the little kid dance on the jar of jam?
Because the top said, “Twist to open.”
 
31 August 1977, News Journal (Mansfield, OH), “Fun Time—The Riddle Box” by A. Leokum, pg. 43, col. 1:
Why did the ant dance on top of the garbage tin?
Because it said : Twist to open.
 
31 July 1980, Lexington (KY) Herald, “Just Kidding, Whatchamacallit, pg. C-16, col. 5:
Why did the dummy dance on the jar of jam? Because the top said, “Twist to open!”—Stacey Hisle, Cynthiana.
   
Google Groups: rec.humor
2 jokes for kids
joewalsh
6/12/97
(...)
Why was the mouse dancing on top of the peanut butter jar?
Because,  it said twist to open
 
Google Groups: alt.humor.puns
Puns of the Weak 01-17-03
Stan Kegel
1/17/03
(...)
Why did the little kid dance on the jar of jam?
Because the top said, “Twist to open.” (Kids Jokes)
 
Google Groups: alt.humor.puns
Kids Puns of the Weak 09-14-04
Stan Kegel
9/14/04
(...)
The fly danced on the top of the Coke bottle because it said, “Twist to open.” (School Jokes)
 
Google Groups: alt.humor.puns
Kids Puns of the Weak 12-14-04
Stan Kegel
12/14/04
(...)
Why did the little kid dance on the jar of jam?
Because the top said, “Twist to open.” (Joseph Rosenbloom)
 
Twitter
Chad Michael | Dance
‏@danceMarketing
Why did the little kid dance on the jar of jam?
Because the top said, “Twist to open.”
4:27 PM - 5 Feb 2009
 
Twitter
Flavia Cristino
‏@flaviabing
@nick_carter Q: Why did the ants dance on the jam jar?
A: The lid said, “Twist to open.”
5:08 PM - 21 Apr 2009
 
Google Books
Sensible Nonsense.. Frank’s Comic Pack:
Humour Pack Series
By Frank Paul
BookBaby
2014
Pg. ?:
Why did the little kid dance on the jar of jam?Because the top said, “Twist to open.”