Guy Gardener wrote:
What happens after the elements causes the yarn to rot?
Is that some sort of health hazard?
We could be talking about the start of a plague.
Depends on what kind of yarn was used. There are pure wools, wool/acrylic blend, pure acrylic, silk, bamboo, cotton, and some really weird synthetics. I have to use acrylic in my craft projects because I'm extremely allergic to wool - can't stand to touch it for even a second, because it's physically painful and causes a rash.
The birds don't mind, though. They're quite happy to adopt bits of stray yarn to use for their nests.