A rather aggressive Bee

I noticed this Bee last night in the flower of a Hollyhock.I thought it was rather strange as normally they go home to roost @ sunset?
  This morning it was still there so I picked it up on one of the wife's nail boards(so that it had something to grip onto) and tempted it with some sugar water,Which it seemed to enjoy? Soon it flew off back to the flowers and that was the last I saw of it! 
   My good deed for the day I thought?
Though the apparent angry response from the Bee confused me a little!