Felines have different gut bacteria than canines. Animals that growl include felines, bears, canines, and crocodilians. Predators in the wild include birds of prey, skunks, felines, snakes and canines. Dogs were important to Wallace, and he spoke of opening a shelter for stray canines. These include the canines, molars, and incisors. Males have relatively larger canines and premolars. The lower canines and lower incisors are enlarged, especially in males, and grow continuously. Premolars are found distal to canines and mesial to molars. The four canines in humans are the two maxillary canines and the two mandibular canines. He had human teeth with large canines. Most species have up to 22 teeth with no canines or anterior premolars. Canines and most premolars, except for maxillary first premolars, usually have one root. The walrus has unique upper canines that are elongated into tusks. Like all dasyurids, the devil has prominent canines and cheek teeth. The diapers used on primates, canines, etc. are much like the diapers used by humans.