Hummingbirds

There are 322 species of hummingbirds worldwide, ranging in size from 2 1/4" (and are as light as a penny), to 8 1/2 ".
21 species make it into the US, with only 8 being common north of the Mexican border. (The largest variety of species live on the west coast.)
A Ruby-throated's body is no larger than the end joint of your thumb.
In the smaller species, males are smaller than the females.
Hummingbirds can fly: straight up, straight down, backwards, forwards, shift sideways, and hover.
Hummingbirds eat: nectar, small beetles, weevils, bugs, flies, gnats, mosquitoes, aphids, leafhoppers, flying ants, parasitic wasps, spiders & harvestmen (Daddy Longlegs). Most are caught on flowers.
Hummingbirds have the highest metabolism of any warm-blooded vertebrate animal, except possibly shrews.
Their flight muscles make up 22-34% of their total body weight.
Their wings beat up to 80 times per SECOND.
They have been clocked at speeds of 50-60 mph.
Their hearts beat 600 to 1000 times per minute.
Quick starvation happens if unable to feed regularly. They must consume their body weight each day.
To survive the nights, when outside temperatures fall, they become dormant and fall into a state of sleep-like torpor, with their body temperatures falling to just above the outside air temperature- 30-50` below their daytime operating temperature.
To make it possible to migrate the 600 miles across the open water of the Gulf of Mexico, they feed heavily, adding up 50%+ of their weight in fat layers. That part of the migration begins far inland in Florida and Georgia, and ends well into Mexico. (Then they fly all the way to Indiana [or Canada, for 4 species]- no wonder they are exhausted!!!)
They have lived in captivity up to 10-14 years.
Their predators are small hawks, falcons, some birds (flycatchers, orioles), frogs, fishes, praying mantises, spider webs and picture windows.
They lay 2 eggs, with a 11-16 day incubation. They are atricial- blind and naked and totally dependent- at hatching and fledge from the nest at 21 days old.