wandering in the night
• (a.) Going about in the night; night-wandering. • (a.) Going about in the night; night-wandering.
Noc·tiv'a·gant adjective [ Latin nox , noctis , night + vagans , present participle of vagari to wander about.] (Zoology) Going about in the night; night-wandering. 
noctivagant Going, or wandering, around in the night.