If the dog's hackles are up, gives a low decibel growl, or engages in a predatory, stalking posture, then there is probably a danger in the environment.
如果狗颈部的毛都竖立起来,或是它发出低分贝咆哮,或是呈掠夺、跟踪姿势,那么周围肯定存在危险。
The lion was stalking a zebra.
狮子偷偷接近斑马。
She claimed that he had been stalking her over a period of three years.