A man was seen prowling around outside the factory just before the fire started.
就在起火之前，有人看到一个男子在工厂外踱来踱去。
《牛津词典》
2
He obeyed, and was promptly arrested as a suspicious character prowling within the precincts of the palace.
他照做了，但很快就被抓了起来，因为那军官认为他是个可疑人物，在宫里的各个角落里鬼鬼祟祟。
3
If something goes wrong—a hungry lizard prowling around for an ant snack, for instance—then a rush of ants returning without food sends waiting reserves a "Don't go out" signal.