Scientists are convinced that dogs can count and researchers at the University of California Davis say they try to convey different messages through the pitch and pace of their barks.

• 小狗会数数，对此科学家们深信不疑。不过加里福尼亚戴维斯大学的研究人员认为，原来小狗们也是会传情达意的，它们叫声高低和节奏急缓的差别代表着不同的讯息。