The meaning of 'take in one's sign'

Question

I searched for the meaning of "take in", and the dictionary showed me several meanings.

1. to understand
2. to receive into one's house in exchange for payment
3. to accept

But the sentence below which shows 'take in one's sign' form and I guess that is a kind of phrase, but I don't know what that means.
Here is the part, which is from 'Baker's blue-jay yarn' by Mark Twain.

A jay can cry, a jay can laugh, a jay can feel shame, a jay can reason and plan and discuss, a jay likes gossip and scandal, a jay has got a sense of humor, a jay knows when he is an ass just as well as you do - maybe better. If jay ain't human, he better take in his sign, that's all.

Answer 1

The "sign" in this case is a metaphor. It's based on the convention that individual shop-owners and craftsmen* had of putting a sign up in front of their business to say what they were: a blacksmith, perhaps, or a tailor, or whatever else. The sign might be written, or, especially in even earlier days, might simply be a picture representing the shop's purpose.

So the "sign" the jay has is all those human-like characteristics being described, as though the jay were in business as a professional human. Twain is saying, well, if he's not a human, he should stop acting so human — take that sign "inside" the metaphorical shop where no one will get misled by seeing it!

_{*Individuals in business by themselves were more common at the time of Mark Twain.}

Answer 2

Twain is implying that the jay has put out a sign (or put a sign out) that says that he (the jay) is human.

If the jay is not human, says Twain, then the jay better take in the (this) sign. Probably in order to not mislead people.

Answer 3

the metaphorical meaning of this description made in the story is much more to be understood by : if the jay is unable to act like a human he should pull down the door of its business. I translated the phrase : "si le geai n'est pas humain alors qu'il tire sa révérence"or "si le geai n'est pas humain alors qu'il ferme boutique" if we want to follow the picture of the shopowner unable to feel as a Customer to manage to sell.