They can, Chris. Some of them even masturbate. What defines asexuality is the lack of sexual attraction. They don't think having sex with people appealing. But that doesn't mean they don't have sex drives. They are too human being, with a body that responds to stimulus. So they can also get aroused to certain stimulus. Though would most likely differ with people with other sexual orientation.

---

They can have sex too, just like heterosexual men can have sex with men or homosexual women can have sex with men or people can have sex with sex workers; sex is an activity that can be done even without sexual/romantic attraction. The same goes with aces. Would they enjoy it? Like it? We don't know. Probably. What we have to keep in mind is that aces, just like other people with other sexual orientation, is different and all fall into a very wide spectrum. Can't say one will apply to the everyone.

---

The cause? Well... we can't say a lot yet, but we're pretty sure that's not because they have traumatic experience, or haven't found the right person yet, or not yet matured, or sexually repressed, or physically ill. The thing is, they probably have little to no difference with sexual person to the extent that people in general don't even think asexuality exists.

---

If you want to know more about asexuality, you can visit asexuality.org for more info :)