They only disappear if you need to find them.

Case in point: The vet. Our cat somehow knows from our behaviour that the visit is today, and disappears off the face off the earth. We had to cancel a visit because we spent more than two hours searching and were late.

So new appointment a day or 2 later, and we watch every step of the beastie like hawks. She disappears behind a cabinet, does not come out, and can be found neither behind or inside. Huh? It turns out the back of the cabinet is open, and there is a really tiny space between drawer and back. If I open a drawer, she goes up/down a layer.

I knew all the time she was less than 50cm from me, and it still took me 15 minutes to figure this out. I've been thinking about creating a tracker, but then , the cat healed enough to lower the frequency of vet visits.

The trick I've found is that when they go in a dumb hiding place act as if it is super hidden and amazing. If you really don't need them then just let them hide and pretend to search for them (never make eye contact but make sure you look like you've looked in the area). It will become their favorite hiding spot quickly and then you get to decide how to use it.

My black cat stays quiet in the living room when I am around. However, once I go to bedroom, he will move around in the house, making lots of noise. His hiding place can be the dark sofa, in front of big tv, etc.

This used to work, but there were so much vet visits in a short time that she switched hiding spots a few times

Yes, but where? Mine rotates that spot on a weekly basis.

Mine tend to stick to the same four or five spots. Those spots do change, but rather infrequently.

My changes their spots depending on temperature.

From warm to cold:

Hall floor

Livingroom floor

Hall box

Livingroom box

Livingroom couch

Bedroom bed

Bedroom bed under the sheets

so you only need a thermometer and machine learning to solve the task? ;)

I just need 1 heated blanket.

And it is always local. I18n the cat would be something to see.

oh come on, you had more then zero training on that model.

You could probably get the other 5% if you have a specific time you set out food.

catnip might introduce jitter.