What is a one-sentence summary of the following article?
Mites affect your bird by burrowing into their skin, often in the area around their eyes and beak. This is known as an infestation of Knemidokoptes pilae, or burrowing face mites. In the early stages of this infestation, the mites are barely visible and will not affect the overall condition of your bird. But you may notice crusty plaques in the corners of your bird’s beak or on your bird’s beak. These bright white deposits will become thicker and more crusty as the mites continue to burrow. The upper area of your bird’s face will appear to have deep burrows or holes, as the mites will dig tunnels or paths in your bird’s skin. The skin around your bird’s eyes and beak will eventually appear cavernous or full of thick, deep tunnels that appear crusty and irritated. Mites can also affect your bird’s legs, known as scaly leg mites or Knemidokoptes mutans. The mites will burrow into the skin of your bird’s legs and lay eggs inside your bird’s skin. As a result, your bird’s legs may appear very dry, scaly, and show white deposits that may turn crusty. The mites release metabolites that severely irritate your bird’s skin, resulting in swelling and scaly skin, or rashes. Mites come out to feed at night, so your bird may be very restless or irritated during the night as a result of bites from the mites. Your bird may also be restless or appear to try to itch his skin against his cage during the day as the mites continue to burrow. In an attempt to remove the mites, your bird may also groom or preen himself excessively, though the mites cannot be removed by grooming or preening. Mites can also burrow and infest your bird’s trachea, air sacs, bronchi or sinuses, resulting in symptoms like coughing, sneezing, or difficulty breathing. Your bird may also start to open-mouth breathe, almost as if he is gasping for air. Watch him when he breathes in his cage for any signs of difficulty breathing or breathing with an open mouth. Your bird may also experience weight loss due to the mite infestation, and he may make clicking sounds or have a change in vocal sounds a result of mites burrowed in his respiratory system. Your bird may have noticeable feather damage, with missing patches of feathers or piles of feathers in his cage. This is as a result of excessive preening or cleaning by your bird in an attempt to remove the mites from his skin. Since mites are nocturnal, they will reproduce during the day and feed at night. Use a flashlight to check your bird’s head and legs for any crawling mites during the night. They may appear as small, red or black spots or specks that move and burrow close to your bird’s skin.

Summary:
Check around your bird’s eyes and beak for any crusty looking area. Examine your bird’s legs for scaly, irritated skin. Note if your bird is restless at night or preens excessively. Check if your bird is coughing, sneezing, open-mouth breathing, or has difficulty breathing. Look for any feather damage or feather loss. Examine your bird’s head and legs at night for swarms of mites.