Infestation is easily spread from person to person through physical contact and often affects the whole family.
The mites, which can hardly be seen with the naked eye, often spread when people sleep together. They are rarely propagated through clothing or bedding or via other shared objects; they survive briefly and normal washing kills them.
The female mite digs tunnels and grooves under the top layer of the skin and lay their eggs there. Young mite forms (larvae) hatch in a few days. The infestation causes severe itching, probably resulting from an allergic reaction to the mites.