The female mite burrows a tiny tunnel beneath the upper layer of skin, laying eggs behind her at the rate of two or three per day. Eggs usually hatch in three to five days. They are spread among hogs by contact and shared bedding. Signs of infestation include inflamed, scurfy skin, restlessness, and itching which causes the host animal to scratch itself and rub against fences and other objects for relief. This activity may compound the skin damage.
Early signs are usually on the face, neck, ears and belly.