Gullivers Travels Book 4

I found it really interesting that Gulliver's main goal was to learn the language of the Houyhnhnms. He was so interested in these horse people. I'm not going to lie, I probably would be interested in them to because they aren't something that I would be used to seeing. Gulliver comes off very selfish because he leaves him pregnant wife to go on another voyage. Like, what kind of man leaves his wife, who is carrying their child, to sail across the sea? I know this book is suppose to be complete satire, but who is Jonathan Swift making fun of by making the house people 'smarter' than humans? That's kind of funny because I was once told that animals are way smarter than we might think.