What should roommates do if they grind their teeth loudly in the middle of the night?

This topic has hit me hard. When I was a freshman, the girl I slept with was grinding her teeth. That was the first time I knew what grinding teeth looked like. At first, I was ignorant. I always thought she liked to dig a mat with her fingers when she slept at night. It's really sour to listen to her grinding her teeth to sleep every night. But it wasn't an orgasm. It was a few months later that I found another girl in our dormitory grinding her teeth. That's right! Two people grind their teeth together, which is super loud. My heart is completely broken. But I'm used to it. I can't sleep without her. In fact, this kind of thing is not intentional by roommates, so you can only get used to it, otherwise it is also a good choice to bring earplugs. All my roommates are perfect except grinding their teeth, and I miss sharing a dormitory with them.