This has GOT to be the most patient, laid-back cat on the planet. The mind boggles.
OMG! I love it.
Delightful watching ! The squirrel looks to me, greatly like a European red squirrel – common on the continent of Europe; but its sub-species here in the UK is pretty rare, and getting rarer – displaced by the North American grey squirrel, Sciurus carolinensis, which species was introduced to Britain in the late 19th century by well-meaning but ill-advised people.
I’m aware that North America has various other kinds of squirrel, besides carolinensis; can any knowledgeable person identify for sure, what variety is the cat-grooming one in the video?
I use Safari. That page is so poorly formatted that about 25% of it is obscured but the sidebar on the left and the video doesn’t play for me. 
Is this the same video?
Yes, but it’s a different cut of the same footage.
The squirrel is a house pet???
I saw a piece on TED or PBS or somewhere about rodents who lose their fear of cats due to being infected with toxoplasmosis. The brain damage is an important part of the parasite’s life cycle. The cat will eat the daredevil mouse, and the parasite lives in the cat’s gut until it is pooped out, where it infects a different host, such as humans. Did I mention that cat poo is considered a tasty delicacy among dogs?