This nest was "under construction". The busy little female would flit away to accumulate more materials for her nest. Spider webs are the critical material needed to bind the lint, string and other items in constructing the nest. I observed one female hummer hovering next to a lady's handbag that had a cotton fringe on it, collecting some fibers for her nest. Only after the nest is completed, do they mate. Two eggs are the norm. Sometimes another female will deposit eggs in another hummers nest, which they will incubate and care for when hatched.