I can only speak from personal experience here, but I had a night time sneaker/eater/getter into things. It was not due to her being hungry or neglected. I honestly don't know what her motivation was, but it happened between the ages of 2-10. She was VERY quiet. I can hear one of my kids sniffle from across the house, but I never heard her creeping around and getting onto counters and into cabinets. Just a few things that stand out to me are, Nestle's Quick in the tub.. she was eating it dry, with a spoon. Bologna and raw eggs in her infant sisters crib, wanted to serve her some breakfast. Tide sprinkled all over her room, ala Carpet Fresh. None of these things were found until I woke up in the morning. There was a short time that we put a latch on the outside of her door because she left the house at around 5am and luckily was brought home by a neighbor that was leaving early for work. Much later, at age 10, she took an overdose of OTC diuretics, which were not anywhere she should have been at 3 in the morning. They made her vomit, and I heard that. Got up and got her to the ER. I never chained her to anything, but my fear that she would harm herself or a sibling was VERY real and I was at my wits end at the time we decided to latch her in at night. It wasn't out of convenience, it was for safety. I think maybe her dad/stepmom went way overboard, and I in no way condone the chaining up of a child, but I can see how they may not have known any other way to keep her safe in her room at night.
Anyway... little angel definitely could have been a night time wanderer. My girl wasn't a sleep walker IMO, she was deliberately doing the things she did. I will never know why, but it seemed to be with purpose, not involuntary at all.
JMO