How do you remove swarmers that are already attached to you? They remind me of the Dead Space swarmers. Unlike the Dead Space variety, there isn't a clear visual indicator or action on how to stop them from attacking you.
Most any area affect power at point blank will do the trick. Run up to a wall and Incinerate or Singularity. Alternatively have a friend shoot it off of you. Since there's no friendly fire they don't have to worry about hitting you in the process.