Spiders are quite vulnerable while waiting in their webs, so different strategies have evolved to prevent being eaten by predators. Tiny Trashline Orbweavers can be common this time of year and their “trash” laden webs can be found all over the garden. These orbweavers rely on camouflage, which includes positioning themselves between bits of jetsam, and when sitting still, resembling bird poop. Must be convincing camouflage as we have not seen one eaten yet…
Hiding between “trash” 
Trashline Orbweaver – Cyclosa sp.