Every morning and every night the hummingbirds fly in and devour the feeder. They say to count as many as you can see, times that by four, and that will give you a rough idea as to how many you have feeding. I counted about 20! So I have approximately 80 birds...I'm going to have to buy more sugar. You can see in the picture just how low the juice is, I filled it up the day before. This year I have two feeders but they seem to like the shiny one best. We've already had to rescue one from my kitchen, the kids love it when I'm holding one in my hand and trotting it out the door.