There’s a lot of information snippets in there, let’s try to pick through it:
‘now they're inseparable and they always do everything together.’ & ‘recently Miya has been always starting fights with Reyes’
I wonder if Reyes is becoming a little hormonal and is experiencing unrequited love. You might want to follow the advice in - https://www.talkbudgies.com/budgie-br...want-eggs.html
and see if their relationship improves.
‘Reyes has learnt many sounds and phrases and it's hard to ever see him sleeping.’ ‘I feel so bad for Reyes because he's so active’
If Reyes is a high energy bird, and is interested in humans enough to learn phrases, then I feel that he may really enjoy clicker training with you - Check out the stickies in the taming & bonding area.
‘It's sad to see him sit alone and chatter all day long while my other birds ignore him’
I have two male budgies, they interact with each other but still enjoy chattering away to themselves, a toy, a perch, a cage bar
, budgies just seem to like hearing their own voice, he isn’t necessarily sad.
‘I have another cockatiel, Hanzo, whos new to our home. Reyes loves to sit on him and annoy him whenever he gets the chance. My budgies and my cockatiel get along well and they always share food and toys.’
Be very careful with this, a cockatiel’s beak can easily hurt a budgie is he decides that he’s had enough annoyance. Supervise interactions and ensure that Hanzo gets some peace & quiet for himself.