Males also ejaculate more sperm when mating with a younger female. The volume of semen ejaculate varies but is generally about 1 teaspoonful or less. Men may also ejaculate without reaching orgasm, which is known as anorgasmic ejaculation. Presence of blood in semen (hematospermia) leads to a brownish or red colored ejaculate. The seminal vesicles, major contributors to ejaculate volume, render semen pH basic. Subsequently, the monkeys had no sperm in their ejaculate. Also, paraplegics may ejaculate seminal fluid but not experience the sensation of orgasm. Nocturnal orgasms, or "wet dreams" are when men ejaculate during sleep. The prostate produces a secretion that forms one of the components of ejaculate. The sage is overcome by desire, causing him to involuntarily ejaculate out of excitement. One way of ensuring that a man produces more ejaculate is to drink more liquids. This condition means that the man will ejaculate with no accompanying sense of pleasure. She simply has the rare female ability to ejaculate. A female's phenotypic quality is a key determinant of a male's ejaculate investment. The components of the ejaculate are comparable to that of the male ejaculate.