Scabies mite, photomicrograph
This is a photomicrograph of the scabies mite. They burrows into the skin, depositing both eggs and feces. A scabies infestation causes intense itching (pruritus) which leads to scratching and damage of the skin (excoriation). If left untreated, the infestation may last for years, and has been called the "seven year itch".