I get Indigos through here every year. One thing that I have noticed is that they like to feed on the ground,but only around shrubs and
trees. I've never seen them on the ground in the wide open. I have birdfeeders next to a 15ft shrub and they eat the
seed that falls on the ground,you never see them around the other feeders that are in the open.
If you have any
trees in your yard try putting some feeders in them or if you have some large shrubs try putting some feeders near them. You could also put some food on the ground around shrubs or bushy areas and see if that works
Hope this helps!
G-Mom