According to the U.S. National Research Council Committee on Recognition and Alleviation of Pain in Laboratory Animals, pain is experienced by many animal species, including mammals and possibly all vertebrates.
Menurut Komite Dewan Riset Nasional AS tentang Pengakuan dan Penghilangan Nyeri pada Hewan Laboratorium, nyeri dialami oleh banyak spesies hewan, termasuk mamalia dan mungkin semua vertebrata .