LSJ appears to show nothing relating to the concept of "into (something)."
Generally, how would "into" be expressed in Ancient Greek? (Specific example: "to crawl into...."
thank you for your inquiry. There usually two ways one can express this (and the alike): either by adding a prefix to the verb (in this case: εἰσέρπειν or προσ-) or by the use of a prepositional expression, i.e. with a simple or even compound verb (-ἔρπειν) and the desired preposition according to what is offered in terms of meanings, e.g.
ἔρπειν εἰς κακόν / ἔρπειν πρὸς τἀγαθά (i.e. εἰς/πρός + acc.)
προσέρπειν ἐπί + dative or εἰς + acc.
εἰσέρπειν ἀμαρτίαις/σπηλαίοις/σκότει etc. (i.e. with dat.)
προσέρπειν + dat.
Always referring to your example, of course. Let me know whether this was clear enough. Good day to you.