Creature Fantasy Writing Tips #1 Sentient and Sapient are Different Words (and You Probably Mean Sapient).
There aren't a lot of resources devoted to writing creature fantasy, animal fiction, xenofiction, or similar human-free works, and I thought I'd help out a little by offering a few tips. My goal here isn't to judge or tell you that you're doing it wrong, but instead, I'd like to help you avoid a few pitfalls or give you more options as a writer. I'm also writing these after my brain is fried from getting my novel work done for the day, so hopefully this'll be coherent and fairly typo-free.
With that in mind, here's your first tip.
Sentience implies an awareness of self as an organism, while sapience implies wisdom, creativity, and near-ish human levels of intelligence. I think what throws people here is all those scifi documentaries about the "search for sentient life" in the cosmos. That phrase doesn't mean they're searching for little grey men with UFOs, it means they're searching for life larger than single-celled organisms.
If you sit outside reading this, turn around, and see that a squirrel has stolen your lunch, it is accurate for you to say "my sandwich was stolen by sentient squirrels." But if the squirrel shouts insults at you, came up with an elaborate plan to steal your sandwich, and this is part of the squirrel's four-year-plan to control sandwiches in your city, the squirrel is sapient. (It's also sentient, but since all squirrels as we know them are sentient, it'd be redundant to mention that.)
"So how far down do you have to go before life stops being sentient?" I've seen studies on sentience in beetles, so I'd assume below insects.
"Wait, but then.... where is the line between sentience and sapience?"
This is a little tougher. Are crows, dolphins, gorillas, or whales sapient? It's a topic for debate, and rather than give you an answer, you can use those as an example of what the line looks like in your own writing.
This distinction can feel a bit pedantic, especially when your favorite scifi and fantasy writers are probably getting it wrong all the time. The thing about creature fantasy fans, though, is that they're here for sapient non-human protagonists, and they know the distinction. You will get angry letters if you mix these up.
That said... if you are writing sentient xenofiction, that's okay! Your audience may be smaller, but a book like Raptor Red by Dr. Robert T. Bakker was immensely popular and influential despite having just a normal Utahraptor as the protagonist. Depending on how you write them, you may get some claims that you're anthropomorphizing your characters. Maybe you want that, maybe you don't. That's entirely up to you. We'll talk about anthropomorphism and disanthropomorphism later on.
That's it for tip #1 =] Just a simple pitfall that writers find themselves in. I apologize ahead of time as you're going to see a lot of non-creature scifi/fantasy fans and authors say sentient when they mean sapient, and it's going to start to irk you as you fix it in your own writing. Just remember to be kind =] Unless you're in a situation where the difference matters, it's probably best to let it slide if someone uses sentience where they mean sapience.
If anyone has any questions about how creature fantasy, xenofiction, furry fiction, or animal fantasy differs from other genres, feel free to ask any questions, and I'll try to answer them.