Do the hadiths and phrases such as "the black dog is a devil" and "camels are devils among beasts" mean that these animals are actual devils, or is the description merely a metaphor for the evil in them?

The discussion concerning the black dog has been detailed previously. Ibn al-Qayyim's intention in likening the black dog to Satan is due to its resemblance to devils in their rebelliousness. Every species of animal has its devils, which are their defiant and rebellious ones. This is supported by what Ibn Taymiyyah mentioned: that the Prophet (peace be upon him) indicated that camels are among the devils, meaning they are of the same class and type of devils. Thus, every defiant and rebellious one is a devil. For this reason, Umar ibn al-Khattab said, when they mounted him on a packhorse that started to trot swiftly, "They have only mounted me on a devil."