Cat introductions

We are trying to do the proper process for introducing two house cats to each other. They have done some sniffing and hissing through the door. Not much, though, because they are each coping with living in a new place, too, and spend most of their time hiding. Shiva hides under the bed or in the walk-in closet (we have a walk-in closet) if there isn't a human in the room. Sometimes she sleeps on her bed by the window, so I'm not concerned. Aya goes to his safe place -- the cabinets under the sink -- and opens the door with his paw in a very human-looking way. There is a cartoon quality to it.

We could probably leave the door open when we weren't home and neither of them would be aware until humans arrived again.