Interesting Reason Behind Why Male Testicles Are Constantly Visibly Moving

If you’ve ever been skinny dipping with a male or, for some reason, had a good long look at your own testicles you’ll perhaps have noticed that they are constantly moving.

Ever wondered why? No? Well, we’re going to tell you anyway.

One Reddit user uncovered the holy grail of facts, learning that male testicles are always visibly moving due to responses to temperature as well as arousal changes. 

If you own a pair of testicles, you’ll know the poor fellas definitely don’t like cold water. 

Oleg Elkov / Alamy

And that’s actually why the pair hang outside the body inside a scrotum - as the temperature inside the body is far too warm for them.

Inside the scrotum, they sit at an optimal temperature of 35 degrees celsius - prime real estate for manufacturing sperm and testosterone.

According to WebMD, the cremaster muscle, which is responsible for movement, expands and contracts according to temperature.

When the temperature is a bit too hot, the lads hang low, and when they’re struggling with the cold they come and cuddle up as close to the body as possible. 

One Reddit user pointed out the oddness of the fact, asking: “Always visibly moving. Who’s watching them?”

Another user replied: “My wife. She gets a kick out of it: I never knew this was a thing until she pointed it out.”

A different person added: "I also noticed this on my hubby while lazing about on the couch one day. It’s like a lava lamp! Mesmerising."

Of course, another reason for testicle movement is sexual arousal.

In the 1960s, William Masters and Virginia Johnson discovered that testicles rise up and even touch the body right before ejaculation. 

Everett Collection Inc / Alamy

They found that in 85 per cent of men, the right testicle rises before the left one - eager fella. 

Masters and Johnson had to get quite up close and personal in their observations and were known as pioneers in research on the physiology of human sexuality.

They were dubbed the ‘Masters of Sex’ in a 2009 book published of the same name that detailed many of their findings.

They stated that movement is very important for testicles, and in order for males to achieve full ejaculation, they must elevate at least partially. 

The masters of sex found that if sexual excitement is sustained long enough the balls can actually double in size and return to normal after orgasm - yikes.

There are all your testicle facts that you didn’t know you needed.