Unless you are very young, your testicles should not go inside your body. Your testicles started out inside your body, but descended into your scrotum through the inguinal canals before you were born. Those canals should close up long before you reach puberty. If your testicles are able to go back through the canals into your body, you should go to the doctor and have it check out.
Sumo Wrestlers, who are generally selected at a very young age, practice 'tucking' their Testicles into their body. When they Wrestle this is a means of protecting them from injury. Continually pushing the Testicles through the canal opening prevent it from closing during maturation of the body.
Testicles are held in the scrotum which hangs them outside the body where it is cool enough for spermatozoan production. The function of the testicles is spermatozoan production.
It seems there might be a typo in your question. Based on context, "scrotum" is the pouch of skin that holds the testicles outside the body in male mammals.
No. But it is better for fertility if they are lower than the core temperature of the body.
In the ovaries and sperm is found in the males testicles : p
Males have testicles.
The slang word "balls" refers to the male testes/testicles.
The testicles are outside of the body because the optimal temperature for fertilization and operation is below that of standard body temperature. This is why wearing "whitey tighties" may cause sterilization (aka they hold the testicles too close to the body which is too hot).
The testicles are located outside the body in the scrotum to maintain a lower temperature than the rest of the body. Sperm production is efficient at a slightly lower temperature, which is why the scrotum contracts or relaxes to regulate the distance of the testes from the body to ensure the ideal temperature for sperm development.
The sperm is reabsorbed by the body, but there may be discomfort in the testicles of some males.
The testicles are contained in the scrotum.
Lots of things come in pairs: Hands, Legs, Eyes, Parents, Testicles...
Testicles are supposed to feel colder than the rest of the body. That's why they sit outside in their own sacs.