Usually when the babies hatch out, the mothers will eat mostly insects to feed the young with. This time of year you will mostly only see males ay your feeders...an occasional female that wants a treat or has lost her young, but the females won't come back till the babies fledge(learn to fly)..then she will bring them to the feeders.
Also, this time of year, there are so many insects and flowers out, that the males hit the feeders less often...but keep feedng them..the babies and moms will be back in a couple of weeks!
I usually only put about an inch of food in the feeders this time of year so it won't go bad in the heat...when I see more action, I will fill them higher.