Coz they do!
If u sit still, rest them on something and just stare at them; they move around! Like they’re looking for a way out or something…
The testes dont move under their own power, no. I’m not a doctor, but I believe the phenomenon you describe (yes, it happens) is the scrotum making fine adjustments to bring the testes closer to the body if the outside temperature has dropped, or to “hang 'em low” if the room* has heated up. A specific temperature slightly lower than body temperature is needed to manufacture healthy sperm.
*I assume you’re not checking this on the street.
That’s nothing – have you ever looked at your hand? I mean, really looked at it?
:eek: (I’ve been waiting for just the right post to use my first “eek!” emoticon!)
This topic came up here a while back and the phrase "Poor man’s Lava Lamp’ was coined.
Is the scrotum made of some sort of erectile tissue? If so this could be a cause of movement seen after you make “adjustments”. I think the skin at least has the ability to tighten up, much like when nipples harden.
posted by mangetout
Has anybody pointed out what a great band name that would be?
Sweet Jesus, now we got a newbie who contemplates his balls.
Yes. they are my band: ‘Poor man’s lava lamp TM’
It’s not just the scrotum contracting, I can do this at will.
Let them hang there and perform Kegel exercises (flex the “clinch off your piss” muscle). They will rise up and down.
There was a video of this floating around on the net somewhere - but I aint gonna go looking for it.
But if u just watch them (without clenching) they start to move around almost randomly.
I find the effect is best observed in or just after a hot bath.
I noticed this phenomenon when I was sitting very still in the bathtub, I think, as an adolescent, and noticed the hair on the testicles moving to and fro slightly, and the testes themselves rotating ever so slightly. I almost couldn’t believe this, so I made a point of trying to observe it again over the next several days or weeks. And it kept happening. If I’m remembering correctly, I looked it up somehow, somewhere, and found out that it’s a manifestation of the process whereby the testicles create a supply of semen. Anybody confirm this?
I’ll confirm this.
It’s as TheLoadedDog describes, the cremasteric muscle and the cremasteric reflex.
BTW, our intramural football team at med school was The Cremasters.
I like to put mine on the mantelpiece and watch them from the couch.
It’s not just the testicles that move when I get near my SO’s genitalia!! :eek: 
To me, it’s more the warmth from the fire, but you are SO right.
What are “testicals” exactly? I heard they are something like Jehova’s Witnesses but I’m not quite sure.
It says a lot about this message board that this is the sort of subject that could come up twice.