Rare Bird: Ruby-crowned Kinglet Comes Daily

This little guy (I assume the same one, I always see the red crown) comes multiple times a day every day since late October. He loves peanut butter, so I feed it to him on a peanut-butter feeder. He will also sometimes sample the suet, but spends more times at the peanut-butter. I understood he was supposed to migrate through the area, but not stay for the winter?