Hi all, I have some bark/mulch around my garden that birds are constantly coming and scratching in. They fling the stuff everywhere over the grass and concrete and it's a real pain. They do this daily.

Are there any discrete products that I could use to repel them? I have seen stuff like this: https://www.pestrol.co.nz/buy-online/pestrol-solar-yard-repeller-elite/ and other products they have, but it appears that the sounds they emit will be visible by humans and pets etc.

I just want to keep birds from scratching up my bark and mulch looking for food!

Thank you