Until today, Leo has not been interested in the doggy door. He would neither investigate going in or out the doggy door. But, today Leo was playing with Darby in the back yard and Darby would cheat by running to the house and darting through the doggy door and then going to the glass doors to look at Leo as he ran up to the house and stared in through the glass.
I let Leo in and Darby ran outside and Leo ran back out the door to continue playing chase. Having watched this for a while, I closed the doggy door so that Darby could not get in and has the laugh of watching Darby bounce off the door and then get cornered by Leo and have to face losing the game of chase.
I opened the door and Darby came in. I lifted the flap and coaxed Leo in. Then the next time I let them out through the glass doors, I let him back in by lifting the flap.
By the end of the evening, Leo had figured out that it was safe to come back in via the flap. He won’t go out, but he will come in.
This is a great improvement because now we don’t have to have a dog barking like crazy when he wants to come in. But, you still have to take him out every hour or so in order to prevent him from having accidents in the house.