Anthony (walks into the living room with his pants around his legs): There's an animal in the bathroom.
Me: An animal? Did the dog come in?
Anthony: No.
Me: Was it a mouse?
Anthony: No.
Me: What was it?
Anthony: An ant.
Me: Oh. Did you squish it?
Anthony: No. Mommy squish it!
Me: Is it still there or do you think it crawled away?
Anthony: It crawled away.
He's right. An ant is an animal. But without knowing which animal you're talking about, you might not fully understand what's going on. This is true in writing too. Specific details make all the difference.