Getting up at night

So my toddler has been an awful sleeper at bedtime. We are making progression though and it’s been a LONG time to get here. She will usually wake 1-2 times a night just come in our room and my husband puts her back to bed. BUT for the past week she gets up, goes in the living room and does god knows what at night. The other night she fed the dog a half bag of treats, nilla wafers, crackers, even opened the tub of yogurt and fed some to her. The food is just in a closet style pantry. She can open the baby proof nobs and the fridge. We don’t know what to do? Set a trap so we can hear her leaving her room? This morning she had all the apples out and took one bite from each. Took her clothes off and put herself back to bed. Just such WEIRD behavior. When we ask her what she’s doing she just says she’s ‘hanging out with Millie (the dog)’.