PLEASE PLEASE DO NOT GIVE SCRAPS OR PIECES OF THREAD TO BIRDS FOR THEIR NESTS!!
IN AN ISSUE OF 'BIRDS AND BLOOMS' IT STATED THE FABRIC AND THREAD GETS WET, THE BABY BIRDS GET CHILLED AND THEN DIE.
If you want to give birds nesting material collect hair from your local salon, barber shop or pet groomer.
There are locations where cotton fabric can be recycled, this is a much better solution for unwanted scraps.
Longarm