Laura, Immature Ruby-throated Hummingbirds have plumage similar to adult female plumage, so you may have young males and females at your feeders. Generally, young male have some gray/dusky streaking or spots on the throat while young females have no or faint streaks on their throats. On the other hand, Birds of North America On-line (the Cornell Labs web site - not free but highly recommended) states that time from laying an egg to the young leaving the nest is 30-36 days. Since we observed nest building by a Ruby-throated on May 26 here in Athens in SE Ohio, it may be a bit early for fledglings up near Canton. Birds of North America also notes that perhaps half of the food consumed by ruby-throated hummingbirds is insects. So if you have almost constant feeding activity, perhaps you do have more than 4 visitors. Good birding, Janet Duerr Athens, OH ______________________________________________________________________ Ohio-birds mailing list, a service of the Ohio Ornithological Society. Our thanks to Miami University for hosting this mailing list. Additional discussions can be found in our forums, at www.ohiobirds.org/forum/. You can join or leave the list, or change your options, at: http://listserv.muohio.edu/scripts/wa.exe?LIST=OHIO-BIRDS Send questions or comments about the list to: [log in to unmask]