Animals are classified into several broad taxonomic groups based on their arrangement and anatomy. These include Protista (elephants, pigs, cows, horses), Neornithes (hedns, fish, birds), Episthians (bees, cats), and Allcidae (alligators, snakes). Herbivores have animals that eat plants and groom themselves to keep themselves clean and well groomed; carnivores have animals that kill their prey and secrete a pheromone to lure the prey away before eating. omnivore animals feed at least partially on vegetation or animal products, but may also obtain protein from other sources. Herbivores and carnivores differ in diet as they usually target different foods.
The classification of animals is based on similarities and differences of anatomy, behavior, physiology, reproductive strategies, and ecological roles. Evidence of animal species can be identified from fossils, molecular biology, DNA, immunology, and physiology. Evidence of Phylogenetics is based on similarities and differences between fossils and other organisms. Evidence of Phylogenetics and Evolution is problematic in that some organisms appear to have originated from multiple ancestral taxa whereas others have derived from only one ancestor.
Insectivores and Carnivores are categorised as Eutherians and Carnivores respectively with Cows, Horses, Deer, Pig, Chicken, Squirrel, Ham, Cat, Rooster, Hedgehog, Salamander, rat, ratchet, bird, fish, bird eggs, air, land crabs, amphibians, crustaceans, snails, and mollusks classified separately with mammals. Within crustaceans, there are three subclasses, namely Protocorine Order (Pentalophytes), Metatheria Order (Araneae), and Eutherian Order (Cetacea). Within the Metatheria, there are four subclasses, namely Prototheria (Spiders, Planthales, Scales, Metatherium), Metatheriums (Crustacea), and Crustacea (Oceans, Mesosubsacteria). Within the Cetacea, there are two subclasses, namely Eutheria and Prototheria.