Something Unexpected

In our backyard, we have some cheap lights we got at Ikea that look like hibiscus flowers. We have often been amused by the hummingbirds that attempt to feed from the brightly colored plastic flowers. Imagaine my surprise to discover a few days ago that a hummingbird had built a nest in the lights. I was more surprised that evening, when I discovered that the nest was active: the hummingbird is returning each evening to sit on the nest. We can watch her quitely, but if she senses us, she does get agitated.

Does anyone know how long hummingbird eggs take to hatch?