One minute there are none and the next they swarm in and if there are fat balls or calci worms on offer it quickly turns into a battle to get to the goodies first. We have come to know it as a Band of Brothers raid and after the screaming and shouting is over, they are gone again leaving behind the empty and sometimes broken feeder.
From a photographic point of view, we encourage them to visit us and love to see them filling our tiny garden space with their in-house squabbling and watching the parents feed their young who are not quite up to the task of pushing their way on to the feeder. Maybe next time!