What does it mean when parakeets squawk really loud?

Answer 1

This means that your parakeet is either scared if you keep trying to pick it up, or if its a male parakeet its calling to the female even if you only have a male parakeet it wants to find a mate.

Answer 2

it means they r irritated something is bothering them if it wont sleep try covering its cage with a blanket. Or change its toys around to keep it occupied try talking to them in a soft voice like aww its ok Im not going to hurt u something like that HOPE THIS HELPS! :)