Katie has a PhD in maths, specializing in the intersection of dynamical systems and number theory. She reports on topics from maths and history to society and animals. Katie has a PhD in maths, ...

You wake up to your partner telling you that you had an entire conversation with someone named Bob last night, or your roommate mentions you were giving what sounded like a presentation in your sleep.

Sleep talking happens when a person speaks aloud during their sleep without being aware of it. The words may be clear ...

It's 2 a.m. The house is quiet, cloaked in the stillness of the night. Then, a shuffle. A door creaks. A child walks down the hallway, eyes wide open but fast asleep. Elsewhere, someone mumbles ...