In one sentence, describe what the following article is about:

One of the most common signs of ear mite infection is the scratching of the affected ear. This ear scratching is because ear mites can cause considerable irritation. The rabbit may scratch his ears with his paw or rub his ears on the ground.  Your rabbit may also shake his head or hold his ear over to one side. Your rabbit’s ears may have reddened or inflamed skin. Irritation from the feces and saliva of the mite causes extreme itchiness, and the rabbit scratches and traumatizes the ear. A severe infection due to ear mites is characterized by distinctive yellow-gray debris and scale that builds up and fills the ear canal. This debris and discharge is tightly adhered to the skin. Attempting to remove the debris causes pain.  Forcible removal tends to peel away the top layer of skin with the discharge leaving a large ulcer behind. Typically in the early stages of infection, close inspection may show scales of skin tightly stuck to the ear canal. If ear mites are left untreated, the weight of the collected debris inside the ear can cause it to drop. The rabbit may develop secondary bacterial infections where the skin is damaged, and infection may spread inwards into the middle and inner ear causing poor balance and a head tilt.

Summary:
Watch for ear scratching. Look for discharge from the ear. Monitor for drooping ears.