"My wife began laughing and rushed over with the baby. There I am sitting at my computer, working, as she sticks my (newborn) son in my face and points to a white dot on his nipple," Andrew Jones, author of the blog Thingamababy.com, told ABCNews.com.
Jones' newborn son was producing "witch's milk" and luckily for Jones, his wife Susan is a labor and delivery nurse and could explain what was happening.
"She wiped it away and squeezed his nipple, and another droplet appeared," he said. "She was all fits and giggles. My first reaction was, 'Stop that!' because who wants to see a baby nipple squeezed?"
High levels of hormones in the mother's body can sometimes transfer through the placenta to the baby in the womb. As a result, both boys and girls can then develop mini "breast nodules" that mimic lactation.
"I was shocked, surprised and amused. I had previously blogged tongue-in-cheek about the potential for fathers to breast-feed babies, and here was proof that males can produce milk," said Jones. "It was an 'I'm going to blog about this' moment. ... It shocked a few people. Mostly it was another parenting curiosity, one of those things they don't tell you in baby books."
About 4 percent of infants produce witch's milk in the first two weeks after birth, according to a study in the Archives of Pediatrics and Adolescent Medicine.
The Joneses knew not to worry because the extra hormones clear out of the baby's body within weeks and, as Jones discovered, the witch's milk goes away.
Lactation Not Just for Mom
Witch's milk, man milk, adolescent milk: According to a reproductive endocrinologist, technically, anyone can lactate under the right conditions.
"Lactation is basically a process that is not just reserved to pregnant patients," said Dr. Sami Jabara, director of reproductive endocrinology and infertility at Texas Tech University Health Science Center in Lubbock.
On Friday's episode of "20/20", Nancy Beatie, the wife of the "pregnant man" Thomas Beatie, told Barbara Walters that she is nursing the Beaties' daughter.
Experts say the reasons a woman like Beatie, who has not recently been pregnant, can nurse a baby also explains how non-mothers can potentially breast-feed.
Inducing Lactation, Without Pregnancy
As most people could guess, hormones during pregnancy prepare the breasts for nursing. Jabara said that mothers who adopt babies and wish to breast-feed can mimic this process by taking hormones, particularly prolactin.
Experts explain that a woman in Nancy Beattie's position, who gave birth to children years ago, could potentially breast-feed simply by using a breast pump and simulating the motion of nursing.
"It's easier to turn on the faucet, so to speak, after having a child," said Dr. Jane Morton, a clinical professor of pediatrics at Stanford University in Palo Alto, Calif.
Morton explained that the hormones in pregnancy permanently change the breast tissue to prepare it for breast feeding. After a pregnancy, the breasts stay "mature" forever.
If a woman isn't pregnant, Morton said, "it's a slow process to gradually increase your production," but it is possible. The key to getting milk to flow from mature breast tissue, either moments after childbirth or years later, is to stimulate the nipple.
"You have a nerve connection from the nipple that goes all the way to another part of the brain that produces oxytocin," said Jabara.
"Even if you have all the right conditions, if the baby doesn't stimulate the nipple, you won't have milking," he said.
Pregnancy and the stimulation of nipples may be nature's way of starting lactation, but Jabara notes there are various other conditions that can set off lactation, even in men.
Lactating Men and Teens
Drugs, fat tissue, tumors, medication, hormone imbalances, and simple nipple stimulation can all lead someone to technically "lactate." Whether it's healthy milk or enough milk to feed a baby is another matter.
Jabara said one possibility could be a tumor in the brain that forces the pituitary gland to produce the hormone prolactin. With the proper nerve stimulation over time, there could be a chance of lactating.
A man simply being overweight could also set the stage for lactating. Jabara said the fat tissue in the body can increase estrogen levels in men, resulting in breast tissue similar to women.
"If you noticed, some obese men have gynecomastia," said Jabara, meaning abnormally large breast tissue and mammary glands for a man.
Enough stimulation with gynecomastia, and a man can start lactating. The same effect can happen for boys or women.
"But a child or a male would not have enough breast tissue to provide all the components of the milk," said Jabara.