QUOTE=Jo-Jo]
I'm about to give up...[/QUOTE]
Nah, don't give up. Maybe you can try letting them see the treat then tossing it out the pet door letting the door close. They might go through on their own to get the treat. They'll get it eventually.
Do I need to get a special kind of pet door to install in the wall? What brands have you used and which do you prefer?
I'm the winning bidder so far on a PetSafe small pet door at $10. Could be a junky one, though.