in-serpo, psi, ptum, 3, v. n.,
to creep on or over any thing; only trop.; constr. with dat. (poet. and post-class.): jam somnus avaris Inserpit curis, Stat. Th. 1, 340: ei lanugo malis inserpebat, covered over his cheeks , Ap. Met. 7, 5, 8.