Hedgehogs are nocturnal. They wake just around dusk and are up and about until dawn. This means while you are sleeping they will discover the joy of konking their food and water dish together in a cacophony that will wake you with a start or just interfere with your dreams.
The best part of this is that while I am gone for the day she sleeps and when I am home she is awake and looking to play. Knowing that she would be awake when I was home was a big part of the decision. I didn't want a pet that needed to play in the day because I knew I would not be home. Interaction is important for your hedgehogs physical and mental health so if you are out at night and only home in the day, this is not the right pet for you.