thanks to all,
i was using a setup asian, cleaning the box i put a substrate of moist toilet paper in the meantime, i took the opportunity to feed him, and he eat a toilet paper.
immediately i tried to open his mouth but it's too late.. he swallowed.
the toilet paper wasn't chemically treated or scented. What worries me is, that he very small (3 cm), the piece will have eat was as the nail of a thumb (as the size of his head).