I sew together the larger pieces to use in baby quilts. Smaller ones I use for FMQ practice sandwiches, zipper pouches and other small items.

Until you have almost been hit in the face with a dead bird dangling by a thread or string wrapped hanging on a pine tree limb, wrapped around their little leg...you may not understand the "harm" of donating your scraps to the nest-building cause. No, i have not left scraps out for the birds but, yes, i was almost struck in the face by a that dead bird .
I can only imagine the terror of a long and frightening predicament that poor bird suffered. Leave nature alone! They survive just fine without our percieved good deeds.

Sandy

I actually burn my snips and strings (cotton or wool only) in my wood stove. Leaves no icky residue (like polyester) and burns down to a fine ash. This has been okay'd by my chimney sweep (who actually took some home for his stove!) as being safe to do since I have a very basic stove. Just a thought...

My chickens always roosted in pine shavings. They dig a hole and plunk themselves down into it. They had access to roosting boxes, but preferred the shavings. My gals always laid their eggs in these holes. Never used straw or any other medium but shavings for them. They free ranged during the day and only slept in the chicken house at night.

So this was my 2 cents....:)

Another option is pet beds. I put my smaller scraps of batting in my scrap bag, which I then sew up as a pet bed.

It would not be a good idea if there is any chance that it could become damp or wet. You would not want your chickens nesting in something that could hold water the way that wool can.