It is no accident that Superman, the original boy scout, the mildest-mannered, the most humane of all superheroes, always has a dog. Obviously, the concept of a super-powered dog is probably the silliest one yet to come from comic books, but whether it was with Krypto or a more mundane dog, I always picture Clark Kent growing up with animals. Unlike the humans in his life, he would never have to explain himself to them, or fear rejection if they saw his true nature. Animals are important in any kid's life, but I can imagine that they would be essential to a superhero growing up with a secret like he had. Any hero as solid and grounded as he is would need to have animal companionship to grow up with and in many ways they could be as important to him as his human relationships, since we're all alien life forms to him.
Late in life I came to understand how much an animal could impact your life. I didn't really grow up with animals, I was a city-kid with two city-kid parents. Apart from the odd short-lived goldfish (who we would wake up to find floating), and a brief few months with a skittish cat, there were very few animals in my childhood. (We didn't even name the cat and my parents had to have put down when it went nuts and wouldn't stop crapping all over the house... In retrospect I can see that they didn't have a lot of choice, but it probably didn't help to have their 10 year old kid yelling "MURDERERS!" at them.) When I moved to California I had the good fortune to housesit for a friend who'd gone back East and needed someone to take care of his dog. Needing a place to live, the dog was purely incidental, but that dog walked every neighborhood in San Francisco with me. She was loyal, smart, and wherever I went I felt safe with her. Her wordless companionship gave me the confidence and the comfort to really explore. Later I was lucky enough to live with two strange cats for 5 years. While I was recovering from illness the cats were affectionate and caring, knowing to snuggle close when I was in pain and give me space when I needed it. Animals were my best and easiest companions in stressful times and I began to understand how teenagers growing up in rural settings had such different experiences of life to me. For them, animals gave them warmth and friendship when their hormones were driving them insane (and driving everyone else away in the process). Comparing the process of learning about a superpower, to the process of self-discovery that people go through, animals would be similarly helpful in that time.
People mock Aquaman for having the weird power of being able to communicate with sea creatures, but imagine how that communion would change a person? It must change a person's psyche quite dramatically to be able to communicate with something that is almost an alien species. We have no idea how whales, dolphins, or even sea anemones think. What are their priorities? Can he talk to sea sponges and barnacles too? How deep does the communication go when they communicate? Let's not even get into super powers which involve transformation into an animal, something like that would affect a human's personality. I once lived in Germany for two years and by the time I left, I was just about beginning to dream in German, which definitely impacted my thought process. Despite their similar roots, German and English use different words to express similar concepts, and there aren't always direct translations for every concept or experience. If being around an animal affects a person deeply, and learning to think in a foreign language does too, then talking TO animals or even becoming one and experiencing animal-shaped thought patterns would have to change a person immeasurably.
If people who grow up with pets and animals in their lives have a different experience of the world, superheroes who do so are bound to have a less lonely view of their reality. It is no wonder that heroes like Daredevil or Spider-Man who grew up in their concrete jungles have a more desperate, fraught quality to their characters. It is a simple enough thing, but from a super hero standpoint, having an animal to unquestionably bond with would be a huge boon to their sanity and I'm glad that Superman, in every incarnation, never seems to lose his childhood dog.