Does your MC have any pets?
How about your other characters, starting with major characters? If not, why not? And did they ever have pets?
And let’s be as specific as possible.
Two dogs, yes. But try two Labradors. Okay, one Black Labrador, and one Chocolate. Names?
Dog people. Cat people. Someone with a house full of parrots. The fact is that animals are important in many of our lives.
A pet can even become, effectively, another character.
At any rate, the relationships between our fictional people and their pets can speak volumes. It can help from a character development point of view.
If your MC has a pet rabbit and you yourself never have, research pet rabbits, as if you were planning to buy one yourself.
It might not seem necessary, if the rabbit doesn’t actually play a significant role in your story, but knowing such details about aspects of the character’s daily life does matter.
The more effort you put into these areas, the more you will ultimately connect with, and come to understand, your protagonist, and other main (and even minor) characters.
In conclusion then, do take the time to consider pets.
This seemingly small tip is one that can actually make a significant different, if you’ve created characters, but they feel somewhat distant, or like cardboard cut-out archetypes.
Pets can give characters the edge, and transform them from names, ages, and traits, into actual people: people readers can believe in, and care about.