I am not a cat fan, or a squirrel fan. I do know from observing squirrels crossing power lines that their dielectric constant is significantly lower than that of air, but I've never figured out how to determine it strictly from observation without actually doing an empirical measurement.
Squirrels act as inductors in DC circuits. Only once though. There's a high current surge that drops to zero as they turn rapidly into a carbon resistor!
We had a different problem. They chewed through the fibre cables between our offices to get the fiberglass sheath for their nests. Eventually they ran Ethernet underground because they'd have broken it again in a couple of weeks.
There goes the high point of my saturday night. Maybe later they'll ask how many cats running in circles you need to levitate a dog wearing a ferrous vest.
This reminds me of a throw-away comment a lecturer made once while discussing the maintenance of telecommunications equipment. He dryly observed that, “Burning technicians don’t smell very nice.”
I don;t think there's a well-defined answer. The "capacitance of a cat" is actually the capacitance of the cat and some other condictor. For purposes of calculating the cat's capacitance you can treat the other plate as a grounded sphere at infinity. It doesn't really matter., you'd get pretty much the same answer with a grounded sphere a few feet away. But for figuring out how much energy you can store before you get an arc, it's all about how far away the second conductor is.
