Arachtober 3 - These are interesting spiders. According to "Common Spiders of North America", the family to which this spider belongs (Uloboridae) are unusual because they don't have venom glands and therefore don't use poison to subdue their prey. Instead, they wrap the prey in a lot of silk, and don't bite until they are ready to eat.
This spider is hunting - it is holding its web taut with its front legs. There is a loop of slack line above the spider's back legs. When prey strikes the web, the spider will release the web so that it collapses, snaring the prey.
This is called the Triangle Spider because its web is in the shape of a triangle. I've never seen one in the daytime.
Arachtober 26e