They are magical little creatures responsible for great amounts of lore. I've posted some information from a book about hummingbirds, along with the link. There are also links to Native American lore and photos of eggs in a nest, following the growth of the babies.
http://books.google.com/books?id=5XXqmTErM24C&dq=mother+hummingbird,+size+of+eggs&pg=PA52&ots=DMvHfH-c3Q&sig=Y-4SkusA3uMqBBv22276WwrPFfU&prev=http://www.google.com/search%3Fsourceid%3Dnavclient%26ie%3DUTF-8%26rls%3DGGLG,GGLG:2005-42,GGLG:en%26q%3Dmother%2Bhummingbird%252C%2Bsize%2Bof%2Beggs&sa=X&oi=print&ct=result&cd=1
Humming birds, on average, weigh as much as three paper clips. They can fly forwards, backwards, sideways, hover and, for quick getaways, they can flip over and fly upside down.
A hummingbird's nest is a tiny cup made of moss, plant fluff and woven together with spider silk. Hummingbird eggs are half an inch long and look like small beans. The babies are the size of a bee, but by the time they're three weeks old they are almost the size of their mother and ready to start flying.
Hummers will fight anything from cats and dogs to humans to defend their territory.
Ruby throated hummers fly 500 miles nonstop across the Gulf of Mexico from Central American to North America. Roufus hummers fly 2500miles twice a year between Alaska and Central America. Some live 15,000feet up in the Andes.
There are 340 different kinds of hummingbirds and they all live only in the Western Hemisphere.
Humming bird birth photos
http://www.spitfirechallenge.ca/hummingbirds%20birth%20may%202006.htm
hummingbird legends and lore
http://www.hummingbirdworld.com/h/legends.htm
Edited for accuracy.