Hummingbirds The Ruby Throated hummingbird is a type of hummingbird that has a red throat. Both the male and female of this species have iridescent green feathers on the upper parts of there bodies. Its wings flap at an amazing 55 beats per second. Hummingbirds eat a lot of spiders, but in South America some spiders try to eat hummingbirds! These bird-eating tarantulas. Large spiders are not the only threat to the Ruby throated hummingbird. The praying mantis hunts for hummingbirds. But the Ruby throated most dangerous predator is probably a small falcon called a American Kestrel and this tiny falcon swoop from the sky at great speed to catch small birds. The female of a ruby throated hummingbird builds a nest on high branches on trees.