So, there’s a difference between sentience and sapience, being self aware, or having consciousness.
Sentient just means the ability to experience feelings.
Pretty much all the animals you mentioned are indeed sentient.
LLMs are not conscious or self aware. They don’t have the ability to feel, so they’re not sentient. There’s an argument that they’re reaching sapience or wisdom, which is the ability to apply experience and tacit knowledge to new situations and complex questions.
Which is the issue. They can become sapient before sentient, meaning they can apply experience to new situations without the ability to use feeling as part of that. That’s pretty much the science fiction AI nightmare. A cold, unemotional, unfeeling computer that can apply logic and experience to problems.