Blackbirds Behaving Badly

I love the blackbirds in our garden, but right now they are testing my patience. They have taken to picking the as yet unripe mulberries off the tree, tasting them, rejecting them  and spitting them (or the blackbird equivalent) onto the path and lawn. I’m more than happy to share the ripe fruit with them, but at the moment no one is benefitting from their scrumping.