Dogs, a cat and a black hole

It is difficult to understand what exactly is a black hole. Astronomers and astrophysicists delight in explaining that matter is absorbed into it and disappears. Bewildering even frightening. What may come out at the other end? well it gets complicated.

Not only humans can be anxious. Some animals too. Not all. As this experiment clearly demonstrates. Paraphrasing George Orwell, can one deduce that some animals are more intelligent than others?

I have never owned a dog, only cats. Many cats as my pages on this site show. And without offending my canine-loving friends, I think my preference is the best.

Video no sound, found on the Internet, author unknown.