Input Please all you Bird people.

Bird netting is cheap and easy to put up. But it will relax over time. Eventually you might find one caught up in it....been there with the garden.
Hardware cloth would be the way to go. Expensive, but permanent.

 

Wrong station...
Maybe try a recording of AOC filibustering...nobody is gonna hang around for that!

 

My boss had tried all the gimmicks. All kinds of flashy/moving stuff. The birds didn't care. They'd been using that barn for tens of years if not one hundred.

 

Look on the bright side...at least they're not pigeons! Messy disgusting birds that make a nest from their droppings. I've cleaned gutters full of pigeon poop. Id rather sweep sparrow poop off my firewood.

My suggestion is netting and/or a cat.

 

Try a compressed air hose poked in the cracks. I can't see them taking to many shots for long.
Bald azzed little things running around!!

 

Single or 3phase?

 

Maybe a photo switch, some bait and a shop vac.....

 

Definitely 3 phase!

 

Ya might be onto something there with using sound to deter the birds.

I have heard a place that uses a predatory bird sound to keep birds away from elec equipment-transformers and such.

 

you're looking at it wrong. bird chit is rich in phosphorus, you need to collect it and sell it to the farmers.
for rafters, you can install spike strips, it keeps them from wanting to roost and nest.