The kitten is traumatised, he has been taken away from all it knows, and is in a strange place with people he has never met before, no doubt smiling at him. ( smiles in cat language is a threat)

He will come out at night to start with, so make sure he can gain access to tray and food within easy reach of its safety zone.

And as Suzy says, keep him and all his belongings in one room to start with..

If he doesnt come out tomorrow, try just taking him out, place him in your arms, close to where he can hear your heartbeat, holding him really close, while gently stroking the top of his head..

You may actually get a purr out of him by doing this..

try and avoid eye contact, if you do look into his eyes, blink, its a sign of 'I mean you no harm' between cats.

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