One other thought is diet... I don't know if you mentioned if you fed them a Linnie mix or not, but I would.
You might want to start a morning routine with your bird, when you chop up fruits and vegetables that you are already giving him... it gives you an opportunity to work closely with your...
Nice!... hopefully they will get along together well.
Never really know with birds... even when getting some from the same clutch.
My two sisters get along really well and they are inseparable... I am fortunate.
Definitely, more than one Linny is best... better for them and better for you, because they won't rely completely on you for companionship.
Plus, with Linnys together, you get to see a more natural behavior.
I let them have a bird bath inside their cage for about an hour or so, and they really enjoy it... You are right about vacuum cleaners making them want to bathe.🙂
They are inseparable... I know their cry when they are calling for each other, and I know their cry when they are sounding an alarm.
They are so cool.😎