So what are these unwelcome pests?

• All humans shed about 5-10 grams of dead skin each week. Some sources indicate as much as three pounds per year. About 80% of the material seen floating in a sunbeam is actually flakes of skin.
• House dust mites eat human and animal skin flakes (Dermatophagoides - "skin eater"). They also thrive on feathers, and even flour! In fact, these mites also love a nice serving of mould as part of their diet as well. In that case allergens become to be even more toxic.
• Dust mites are one of the main causes of Atopic Dermatitis in children.
• Estimates are that dust mites may be a factor in 50% to 80% of asthma cases, as well as in countless cases of eczema, hay fever, and other allergic ailments.
• Much smaller than a grain of sand, dust mites are too tiny to be seen with the human eye.
• House dust mites are 0.2-0.3 mm long and translucent. They have eight legs, no eyes, no antennae in front of their bodies (resembling a head).
• House dust mites are part of the Arachnid family — relatives of spiders, chiggers and ticks.
• The house dust mite is not the main problem in itself. Dust mites don't bite or transmit diseases.
• The average life cycle for a male dust mite is 20 to 30 days, while a mated female dust mite can live for 10 weeks, laying 60 to 100 eggs in the last 5 weeks of her life.
• The dust mite survives in all climates, except at high altitudes where reproduction is halted.
• House dust mites are nearly universal in occurrence - a typical bed mattress may contain anywhere from 100,000 to 10 million mites.
• Given enough food supply, each mite can process and package up to twenty faecal pellets per day. With a hundred  million allergenic particles disturbed when people move around in bed, it is no wonder that dust mite allergy sufferers experience a worsening of symptoms at night time.
• With as many as 18,875 mites counted in a gram of dust (the weight of a paper clip) the term 'the air is thick' takes on a whole new meaning.
• Dust mites have been blamed for allergies, hay fever, dermatitis, rhinitis, and asthma. Exposure to their feces or body parts can cause asthma in children and create the risk of respiratory disorder.
• If you lay on a carpet that is infested with dust mites, you may develop red itchy bumps as a result of the allergen coming in contact with your skin.
• Dust mites are the source of one of the most powerful biological allergens!
• One of the more important proteins responsible for the allergic reaction is DerP1, a protease digestive enzyme found in mite feces.
• Dust mite allergen is the number one cause of perennial allergic rhinitis.
• At least 10% of the human population and approximately 80% of allergy sufferers are allergic to proteins that are found in the waste produced by dust mites and in the decomposed bodies of dead dust mites.
• If you often wake up with congestion, a runny nose, watery eyes, itching, or sneezing, then you are probably allergic to dust mites.
• If neither parent is allergic there is still a 5-15% chance that the child will develop allergies. For a child with allergic parents, this increases to 25%. If both parents are allergic there is a 50-60% chance of the child developing allergies. When both parents have the same allergic disease the risk increases to 80%.
• In the last ten years, the privately run Auckland Allergy Clinic has seen allergy prevalence increase by 50%. Public practice has seen an increase from 40 patients per month 2 years ago to 150-200 per month today. There is a waiting list of 8 months.
• Exposure to high allergen levels in early life is a risk factor for the development of allergy.
• It is now generally accepted that allergy is a developed country phenomenon; it doesn't exist in third world countries. There seems to be a connection between standard of living and allergy; the better our homes and living standards are the more allergies we have.
• Our warm, well-insulated, thickly carpeted homes provide the perfect breeding grounds for dust mites.
• Your bed is the perfect environment for dust mites; they love to burrow into fabric and feast on your dead skin cells. (Humans shed two to three pounds of skin a year — plenty of food for tiny dust mites.)
• Ten percent of the weight of a two year old pillow may be composed of dead mites and their droppings. How old is your pillow?
• Carpets and household upholstery also support high mite populations.
• Dust Mites create household dust that many filtration systems miss.
• Allergens (faeces) measure 2 microns, and their dead carcasses measure 250 microns.
• Doctors believe that dust is one of the largest mediums of human infection.
• Germs have no means of locomotion except to attach themselves to particles of dust.
• 42,000 dust mites can live in only one ounce of dust. 40 pounds of dust is generated per year in 1,500 square feet of space. How big is your home?
• Dust hosts 15 species of dust mites.
• It is estimated that you breathe in 2 heaping teaspoons of air particles per day, including dust.
• Bedrooms may well be where the largest population of dust mites reside.
• Dust problems increase due to heat, moisture, and humidity above 70%.
• Dust accumulation in electrical equipment, computers, air ducts, etc. reduces efficiency and in some cases can damage equipment.
• Popular cold water wash cycles have added to the problem of dust mites infestation as cold water does not harm dust mites!
• As dust mites are totally blind, they have evolved a system to decide whether particles they have just come across are food or waste they have already extracted all nutrients from.
• House dust mites cannot drink. They obtain water partly from their food but the bulk of their water needs is obtained through a mechanism of hydrophilic (water-loving) crystals in their armpits.
• In Auckland, the relative humidity is above 80% all year, which explains the very high levels of dust mite counts in this city environment.
• The latest findings further suggest that there is no significant advantage to using a HEPA vacuum cleaner to reduce exposure to airborne particles like dust mites. The findings appear in the January 2006 issue of the European Journal of Allergy and Clinical Immunology.
• There is no way to completely eliminate dust mites, but there are methods to control them through chemical control or avoidance.

How do they harm us?

They eat waste human skin flakes and turn this into highly allergic waste (poo) that we breathe in. This waste, along with waste from dead dust mites, is so light it floats up into the air and goes into our lungs, throat, nasal cavity and so on.

This can cause an allergic reaction in people resulting in blocked nose, sneezing, poor breathing, itchy eyes, itchy throat, sore throat, skin irritations and asthma. This allergic reaction may also worsen skin conditions such as eczema!