But I try not to think with my gut. If I'm serious about understanding the world, thinking with anything besides my brain, as tempting as that might … - Carl Sagan

When you look more generally at life on Earth, you find that it is all the same kind of life. ...It uses about fifty fundamental biological building blocks, organic molecules. ...with trivial exceptions, all organisms on Earth use... an enzyme, to control the rate and direction of the chemistry of life. ...a nucleic acid to encode the hereditary information ...the identical code book for translating nucleic acid language into protein language. ...At the molecular level, we are all virtually identical.

"What worries me the most,' she continued, 'is the opposite, the possibility that they're not trying. They could communicate with us, all right, but they're not doing it because they don't see any point to it. It's like..." — she glanced down at the edge of the tablecloth they had spread over the grass — "like the ants. They occupy the same landscape that we do. They have plenty to do, things to occupy themselves. On some level they're very well aware of their environment. But we don't try to communicate with them. So I don't think they have the foggiest notion that we exist."

So far as I know, childbirth is generally painful in only one of the millions of species on Earth: human beings. This must be a consequence of the recent and continuing increase in cranial volume... Childbirth is painful because the evolution of the human skull has been spectacularly fast and recent.