They love their food, they love company, but when the door opens, they love to get out. Some can even get over the barricade at full height, but the food being right there hinders them. I have the door closed, barricade at half height, set the food between the barricade and the door, open the door, step in. Then I’ve been able to raise the barricade while they eat. This may work for a few days.
How To Get Through The Door–Without Kittens Getting Out