The mite that causes scabies in humans is microscopic and almost impossible to see without a magnifying glass. The female mite burrows just beneath your skin and produces a tunnel in which it deposits eggs. The eggs mature in 21 days, and the new mites work their way to the surface of your skin, where they mature and can spread to other areas of your skin or to the skin of other people. The itching of scabies results from your body's allergic reaction to the mites.

Close physical contact and, less often, sharing clothing or bedding with an infected person can spread the mites.

Dogs, cats and humans all are a ffected by their own distinct species of mite. Each species of mite prefers one specific type of host and doesn't live for long away from that preferred host. So humans may have a temporary skin reaction from contact with the animal scabies mite. But humans are unlikely to develop full-blown scabies from this contact, as they might from contact with the human scabies mite.