constant squaking

ok as most of you no i i have had 3 common grey tiels rehomed with me due to a dumd law in london anyway ever since they have been here it is like the 2 males won,t stop squaking morning afternoon night the three have been together from the day my friend bought them if i seperate them it gets louder but if i put them in a dark room they shut right up i tried putting them in with my other tiels and my other tiels attack them so that is out of the question any tips