Mynahs and Starlings in the Roof Space?

Try chilli oil in a water pistol. Good for possums too.

+1 for vinegar, or if you have a cat, place a few piles of the (used) kitty litter at any hole you think is an issue, and they clear out quicker than a prophet on prayer-mat-shaped-land-mine.

I had a similar problem a year ago so I got a quote from a bird-remover. The price didn’t concern me, but I stupidly asked how his method worked. He explained he scattered cardboard pads with sticky poison (facing upwards) in the roof space. The birds stand on the pads, the poison transfers to their feet, they lick their feet clean, then they die an agonisingly painful death. He didn’t say the last part. I just inferred it from the word “poison”.

That thought upset me too much to proceed. Instead I bought a supersoaker, filled it with white vinegar, and sprayed the inside of my roof space. It makes a god awful smell. The birds haven’t been back. Thankfully you can’t smell the vinegar inside the house because inside the roof space you need a gas mask.