Balls

[Goth_ben]

sometimes my balls hang low and sometimes they become quick tihgt and not saggy at all. why is this?

[PhillyBby]

Because they cling close to the body to keep the sperm warm otherwise the cold would kill them

[Bobby]

When it's cold outside they hang close. When it's warm, they loosen up a little. It just depends on the temperature.

[Antares]

Yep, its true. The temperature difference affects if your balls hang low or stay close. This is to keep the temp right to keep sperm alive and produced.

[Patchy]

Its like climate control for your testicles, when there too hot they drop to keep cool and not take as much heat from the rest of your body. and if your testicles are cold they move closer to your body to get more heat.

[The Entertainer]

Sperm is (strangely) best produced at temperatures that are slightly different to the natural body temperature. Thats why your testicles are outside your body. Its a stupid evolutionary thing that will over time, hopefully disappear. Quite a lot of animals have internal testicles.
Any-hoo, when its hot outside, youll need to cool down to keep the temperature inside your testicles nice and regulated. The surface area of your scrotum will increase too, which is beneficial for the same reason.
When it is cold, to keep sperm production up, your balls will retract, get close to your body, and help retain the temperature inside your scrotum.
Thats the incredibly sketchy science behind it all