Scabies mites (Sarcoptes scabiei) are parasites that need a human host in order to survive. The female parasite burrows under the top layer of the skin to lay her eggs. The skin becomes inflamed, red and swollen in response to the presence of the eggs, the mites themselves, and their wastes.
Scabies is spread by direct contact with a person or animal that is infected, and can also be passed on via the sharing of bedding, towels or clothes.