Why do testicles move on their own?

Men are definitely very concerned about testicles, because it may be related to male reproduction. The testicles are located inside the scrotum and are controlled by muscles, which are a special type. The muscles they control are smooth muscles and skeletal muscles. Smooth muscles are fixed and have nothing to do with our own willpower. So why do the testicles move unconsciously?

But you can't control it. You're trying to do a cremaster reflex.

The testicles are located in the scrotum, one on each side, and the left side is generally 1 cm lower than the right side. The testicles are slightly flattened elliptical, with a smooth surface, divided into inner and outer sides, front and back edges, and upper and lower ends. The front edge is free; the back edge has blood vessels, nerves and lymphatic vessels entering and exiting, and is in contact with the epididymis and the testicular part of the vas deferens. The upper and back edges are attached to the epididymis head, and the lower end is free. The outer side is convex and the inner side is flat. The testicles grow rapidly with sexual maturity, and shrink and become smaller with the decline of sexual function in old age.

From the septum arise numerous connective tissue septa that divide the testicular parenchyma into many testicular lobules.

The testicular lobule contains the convoluted seminiferous tubules, the epithelium of which can produce sperm. The connective tissue between the tubules contains interstitial cells that secrete male hormones.

The seminiferous tubules combine to form the straight tubules, which enter the testicular septum and interweave to form the rete testis. From the rete testis, 12 to 15 efferent ductules emerge, exiting the upper part of the posterior edge of the testis and entering the epididymis.

Testicles are male internal reproductive organs. Normal men have two testicles, one on the left and one on the right side of the scrotum. Testicles are oval and grayish white. Adult testicles are 3.5-6 cm long, 2.3-4 cm wide, 2-2.8 cm thick, and each testicle weighs 16-67 grams. Generally, the left testicle is about 0.5 cm lower than the right testicle. Some people have one testicle that is larger than the other, or one that is higher than the other. If the difference is not too big, it is normal.

Interstitial cells produce androgens, which are closely related to male secondary sexual characteristics and physiological functions.