Mice In My Beehive

I broke down my beehive to see if I could tell what happened.  I discovered that there was a nest of mice in the bottom hive box.  I suspect that is what did in my hive.  I was surprised because I had the bottom board turned over to the narrow opening.  How they got in through that small slot I have no idea.  I’ll have to make sure they do not get in next year as I think that is why I lost the hive.  There was plenty of honey in the hive and the remnants of a cluster.