I'm sorry, wtf is this???

I was watching my betta in his tank when I realized he had a little white spot on him. My first thought was ich, but then I realized it was moving. Upon closer inspection, I found an entire amry of little white bugs in my tank!!! They're mostly in this white corner with the snails, eating something? They're all walking around. I've never seen these before. I have no idea what they are or how to get rid of them. Any help is appreciated!