It's true that eunuchs cannot ejaculate, but it's false that they cannot engage in sexual intercourse. This is because the pituitary gland responsible for stimulating libido still exists, and the tool for intercourse—the penis—also remains functional. Therefore, within the palace precincts, there were frequent scandals involving concubines, female officials, and maids engaging in sexual relations with eunuchs. Consequently, eunuchs did marry wives, though they could only have intercourse without the ability to ejaculate.
Eunuchs do not grow noticeable facial hair, lack an Adam's apple, have a finer voice, speak in a feminine tone, and their movements resemble those of women rather than men, making them "neuter" individuals.
Since the Eastern Han Dynasty, only castrated individuals were used as eunuchs. This was due to the fact that within the inner chambers of the palace, from the Empress Dowager, Consorts, current dynasty’s Empresses, Concubines, to the palace maids, there were many female residents.
For ordinary people to become eunuchs, they must first undergo castration, which means...