3 female Ruby Throated Hummingbirds. The males of the species are insane. They fight all day long to protect their feeders...be there 2 or 10...a very exhausting way to live. This appears to be a mother and her 2 chicks. After fledging the mother will allow the chicks at the feeder for about 2 weeks. After that they're on their own. It's a dog eat dog world in the race to bulk up for the flight to South America in the Fall.