Crabs (lice) and scabies are parasites transmitted through skin to skin contact. They can also live on bedding, furniture and animals. They can live anywhere on the body. The lice attach to the hair shaft and can crawl around causing itching. Scabies burrow into the skin where they lay eggs. It also causes extreme itching and red bumps. Both crabs and scabies can be treated with lotions and creams available in the pharmacy. No prescription is needed. Crabs and scabies do not cause disease but constant scratching can cause a skin infection.