neither rain nor hail nor sleet nor snow may stop the mail but dog bites do. the highest risk cities for postal workers, houston, los angeles, cleveland and san diego. >> how do you keep from being bit? >> you have to be big. you have to be bold and you have to be dominant in your personality when you see a dog doing something. >> reporter: that's the advice for grownups. for kids, experts say don't approach dogs you don't know and if a dog attacks, roll up in to a ball or get a cat. david wright, abc news, los angeles. >> yeah, get that cat. that's the best cat ever. >> hero cat. >> check out some chat points. signals a dog may bite. almost sounds like a human. tense body, stiff tailed, furrowed brow, pulled back ears, eyes rolled so the whites are visible. some other ones, as well. >> yawning. >> that's a strange one. >> yeah, a yawning dog is