VICIOUS Baby Cockatiels!!!

[crystalchik]

I need HELP!!!!!
I am hand raising 4 baby cockatiels and three of the four (the 3 are related, and the other is from a different clutch) are VICIOUS!!! And please dont try to tell me that they are just making hungry baby sounds, I know what those sound like! I am not completely new to raising cockatiels, I have hand fed a couple in the past. They open their beaks, HISS (if you have ever ticked off a cockatiel and gotten it to open its beak and hiss at you...that's what this sounds like!), and they even lunge at my hand or at the sight of me! I know they have no intention of eating because I have JUST FED THEM!!! When I put my hand down in there, they lunge at my hand a few times and sway back and forth, beaks open[like the parents did], and scream and hiss. I touch their faces and eventually they calm down and stop. I do this every time I walk into or by where they are (countless # of times) and they have not gotten any better.
What gets me is that, come feeding time, they revert to their "Im hungry feed me!" cute little cries. But as soon as their full, they switch back to their little demon selves!
I have never seen this before and cant find any info on it so any help would be appreciated!! They are now 19 days old and I pulled them 5 days ago.
HEEEELP!!!!
From the concerned mother,
Crystalchik

 

[Chicky Tocks]

I found this online. My experience is mostly with budgies, but the cockatiel can't be far removed.

I thought the cute part was sitting by the cage and reading them a book. Hehe! Another thing I used to do was to put a bell in the cage and poke the bell with my finger. Birds are curious and before I knew it, my budgies would be ringing the bell with me.

http://www.bellaonline.com/articles/art37898.asp

 

[Goattalker]

I have one clutch hatched now, and another due to hatch next week. What I have found that works for me, (I had a hisser too) is to pick them up, with my hand over their wings, cupped in my hands, and make them sit with me. I am not hand feeding, and so far my babies have been tame. I hate that hissing nonsense, and when one of my adults pull that stunt, I reach into the cage and it is up, up lesson time. It doesn't take them very long to associate work with hissing, and the hissing stops.