Bazongas. Boobies. The girls. Whatever you call them, breasts are surprising for those that have them and those that don’t. Turning up around puberty for women, estrogen and growth hormone cause the development of breasts, which are made up of glandular and fatty tissue.

Here are five more things you may not have known about the mammaries. After all, they are our breast friends.

1. Some women can orgasm via breast stimulation

Two high-profile sex educators conducted an in-depth study to bolster claims that women could reach orgasm through breast stimulation alone. Dorian Solot and Marshall Miller, authors of I Love Female Orgasm: An Extraordinary Orgasm Guide, reported that 1% of women in their research told of their ability to orgasm through playing with their pair.

2. Boobs are more fraternal twins than identical

Everyone has asymmetrical features: an arm longer the other, a foot larger than the other, even a breast larger than the other. In a study published in the International Journal of Clothing Science and Technology, the right breast was found to be on average larger than the left.

3. Breasts can weigh about as much as three bricks

Imagine carrying three bricks around all day every day and then sleeping with them on your chest. The average bra can support breasts that weigh between 0.23 kilograms (half a pound) and 9 kilograms (20 pounds), about the weight of three bricks. That’s heavy stuff.

4. And if you like ‘em large, you’re probably not rolling in dollar

A 2013 study found that men who “lacked material goods,” or who were from a lower socioeconomic background, preferred women with larger bosoms, as this higher fat content may indicate the women have access to better resources. In fact, these researchers found that those from a low socioeconomic background desired a woman with bigger boobs more than men from a medium socioeconomic background. And, in turn, men from a medium socioeconomic background fancied a larger pair than men from a high socioeconomic background. Essentially, the poorer the man, the larger the handful preferred.

5. Everyone stares at your breasts. EVERY. ONE.

According to a study where women and men were fitted with an eye-tracking device, both were found to look at a woman’s boobs instead of her face but men do it for longer. So women do boob-watch too but they’re just quicker about it.