beehive protection

I came home today to see a lot of activity in front of the hive. I wonder if my hive was getting robbed out because of the "agitated" behavior. I took video: https://www.youtube.com/watch?v=Clj9rT5nOqU and after I reduced the entrance here is what they look like...

Hello this is my first post here, love the site. I have came up with a good idea i use and i will tell you how it help me. This is Not a complete protection against Tornadoes, Bear Attacks or Human Robbers. http://img23.imageshack.us/img23/9703/projectt.png This is Good to help fight: (Cement...