Yes, I do see the cardinals hopping on the ground a lot. I actually put a few seeds in a dish on the ground right next to the feeder (which is below the tree they prefer to hang out in, and where their little baby lives), and when I checked on it a few hours later, no seeds taken but that thing was crawling with ants. 
It’s also right next to a little space in my fence where the chipmunk likes to come in. I think the chipmunk will likely clean out the seeds on the ground before the cardinals do. We’ll see if I find a good compromise.
