Lists 1: Found in bags left for re-use

Half-eaten string cheese.
Popcorn.
Potting soil. Once rich, now disappointed.
Human hair. Subsets: curly, grey, brunette, wavy.
Dog hair. Mixed.
Earwig. Subsets: living, dead.
Tears. Subsets: oily, spattered, pooled.
Orchid bloom.
Snow.
Laugh.
Shadow of cat.
Hole of mouse.
Sigh.