A Christmas riddle is:

Q: How do you know when Santa is in the room?
A: You can sense his presents (presence).

The joke has been cited in print since at least 2010.


Twitter
Seth Caddell‏
@SethCaddell
How does Darth Vader know where Santa is?  He can sense his presents.  Jr high joke that I thought I would share.  #stumin
10:15 PM - 16 Mar 2010

Twitter
Giggle On®‏
@GiggleOn
For @andreahess Q. How do you know when Santa’s in the room? A. You can sense his presents.
11:38 AM - 14 Dec 2010

Twitter
Santa Claus Atlanta‏
@SantaAtlanta
Q: How do you know when Santa is in the room?
A: You can sense his presents
10:34 AM - 29 Sep 2011

Google Books
Christmas Crackers
By Matt Wilce
Lulu Press (Lulu.com)
2012
Pg. ?:
How do you know when Santa’s in the room?
You can sense his presents.

Twitter
Corny Jokes‏
@cornyjokes365
How do you know when Santa is in the room? You can sense his presents!
12:22 AM - 25 Dec 2012

Reddit—Jokes
Santa is nearby…
submitted December 23, 2016 by reactorfox
I can sense his presents

10 December 2012, Daily News (Warwick, Queensland), “Joke of the Day,” pg. 2:
Q: HOW do you know when Santa’s in the room?
A: You can sense his presents.

Google Books
Christmas Jokes
By Delphon Coker
Xlibris COrporation (Xlibris.com)
2016
Pg ?:
Joke 131: Name one way we can tell that Santa is around?
Answer: We can sense his presents.

Reddit—Oneliners
You know when Santa’s in the room because you can sense his presents.
submitted December 4, 2017 by madazzahatter