I just installed a new "Grandpa's Feeder" 3 days ago. It has a lid that opens and closes when the hens step on the pedal and is taking some time for the chickens to get used to. As of this morning I've seen two of them figure it out and are using it properly, but the other three don't seem to get it yet. The instructions say to leave them with no other food and they will eventually get used to it. Since it's been three days, should I worry about the 3 I haven't seen use it?