Snips and snails and puppy dog tails… check out all the essential things to know if you're expecting or raising a boy!

1. Blue Wasn’t Always for Boys

You know you’re in the boys section of the store when everything is blue and covered in trucks, dinosaurs, and sportiness—so how funny is it that pink was originally marketed as the more masculine choice for babies? Pastel colors were popularized in the early 1900s, but it wasn’t until the 1930s that consumers started to prefer blue on their boys.

2. Boys and Girls Look the Same, at First

During the earliest stages of embryonic growth, babies’ genitals are indistinguishable. Both boys and girls develop the same genital nub until about seven weeks of growth. Once testosterone begins to kick in, your little guy’s “little guy” will grow more prominent and gender will become visible.

3. You Can See He’s a Boy by 18 Weeks

Ultrasound is the least invasive way of finding out the health and gender of your baby. While gender differences do become noticeable around the second month, ultrasound technology is not yet powerful enough to see them. When your baby is closer to 18 weeks old, he likely will be large enough that, as long as he cooperates, you should easily see his bits and pieces.

4. He Might Have Breasts, for a Bit

During the nine months of your pregnancy, he’s been exposed to high levels of estrogen. When you give birth, his body might react to the withdrawal of estrogen with temporary swelling of his breast tissue. It’s totally normal and nothing to worry about. In a few weeks the swelling will disappear and you’ll forget it ever happened.

5. Erections Are Normal

Many new moms and dads feel worried and surprised the first time they notice their newborn son has an erection. Erections in a newborn are totally normal, and in fact he was even having them in the womb. A word of warning,  if you're about to change his diaper and notice he has an erection, you might want to grab a towel or put his diaper back on for a few more seconds—erections in a newborn are often a sign that his little bladder is full.

6. Circumcision Rates Are Dropping

One of the first medical decisions you will have  to make for your son is whether or not to have him circumcised. The surgical removal of the foreskin, or glans, can be done for religious and/or cosmetic purposes. While rates for circumcision are steadily declining, approximately 75% of boys are still being circumcised. Discuss your options with a pediatrician, talk to your husband, or do some research to help decide what is right for your family.

7. Boys Are Bigger At Birth

The largest baby ever born was a whopping 22 pounds—and a boy. In general, boys are 3-4 ounces heavier than girls at birth. There is some thought that those few extra ounces help contribute to a slightly longer delivery. On average, delivering a baby boy takes 30-45 minutes longer.

8. Boys Like Crowds

Researchers have discovered an interesting fact about baby boys' brains—while infant baby girls prefer looking at and studying pictures of individuals, boys are much more attracted to photos of groups of people.

9. Boys Are Busier

In general, boys are more likely to be on the go. While there is no real difference between boys and girls as to who will crawl or walk first, once they get moving, boys are more likely to keep moving.

It is thought this increased focus on mobility is what puts boys a month or two behind girls when it comes to speech and language skills, but no worries, boys typically catch up to girls by the age of three.

10. Boys Are Daredevils

We know this one is obvious, but turns out, it's backed by science. In studies it was shown that boys had far fewer startle responses to loud stimuli than girls. Also, when babies were presented with toys that their mothers made negative reactions to, boys were much more likely to ignore the warnings than girls. If you're having a boy, it might be the time to start investing in hair dye—you're definitely going to go gray!