BTW David, love the pictures of the two kitties together. Had a brother/sister pair of Siamese who did the same thing. Sadly the brother became ill at four years of age, nobody could figure out what was happening and he passed away. Still have his sister, she's probably 15+ years now, but still doing great.
Her entire personality changed after her brother died. They used to lay out in the sun, play in the yard, try and catch birds, etc. Ever since he passed away, she is strictly a house cat, maybe once or twice a year she may go outside in perfect weather, but I think cats have a long memory and she misses her brother.
We thought they were brothers when we adopted them. But their adoption papers state they're born a couple weeks apart. We believe they were rescued from the same location, and same group of cats. But don't know if they're actually related
The funny, and problematic, thing is that "my" cat, Dash, is the younger (and most likely the runt of his litter) and has learned everything he knows from Mango. And he continues to emulate Mango. Which drives Mango bonkers, because Dash violates Alpha / Beta cat rules of hierarchy. The latest example, is that we made Mango a dedicated 'escape' space. But Dash eventually realized what was going on, and wanted to take advantage of it. Se we had to expand. And this is what snooze-time currently looks like: