Who’s in Bed with You? House Dust Mites

First published in Woopi News in November 2025

Do you believe me? Let’s pull back the covers and see who’s living under your sheets.

House Dust Mites (HDMs) thrive where there’s moisture, warmth, and food. They can’t drink water, so they absorb it from the air — or from sweaty bedding throughout the night — once relative humidity exceeds 55%. They prefer temperatures above 25°C (like a warm bed) and feed on human and pet dander (shed hair and skin cells), cellulose from textiles (such as curtains, carpets, and soft toys), as well as pollens and microbes.

Fun fact: Each person sheds enough skin cells to feed around one million HDMs every single day. What’s wrong with sharing your bed with millions of Dust Mites? Nothing — unless you’re allergic to them. HDMs don’t bite, spread disease, or cause health problems unless you’re sensitive to their allergens. However, HDM allergy affects around 22% of the population, making it one of the most common allergies worldwide.

Around 85% of asthma sufferers are allergic to HDMs, which are also a leading cause of hay fever and allergic asthma. HDMs produce and excrete numerous allergens, including proteins and microbial by-products found in their faeces. Speaking of faeces, they produce around 40 trillion faecal pellets in a mattress every three months.

Symptoms of HDM allergy include itchy or watery eyes, sneezing, an itchy, runny, or blocked nose, dry persistent cough, wheezing, and eczema. Symptoms tend to worsen at night or upon waking. Unlike pollen allergies, HDM allergies aren’t seasonal — but symptoms vary with humidity and temperature indoors, and usually improve when you’re away from the source.

Solutions for Reducing Dust Mites:

If you suffer from HDM allergies and are ready to take control, start with the bedroom — it’s their favourite habitat.

1. Reduce HDM levels by replacing carpet with hard flooring; and curtains with timber or metal blinds that can be wiped with a slightly damp microfibre cloth.

2. Maintain indoor humidity between 40–55% using a dehumidifier or refrigerated air conditioner.

3. Discard old soft furnishings. Replace mattresses and wool or feather-filled doonas every ten years, and pillows every two years.

4. Wash sheets and pyjamas weekly in hot water (at least 55°C), and pillows, blankets, and doonas every two months. Choose washable toys for children with HDM allergies. Air rugs, bedding, and mattresses outside on hot, dry days whenever possible.

5. Don’t make the bed straight away. Leave the covers off in the morning to let the mattress dry out.

6. Vacuum daily with a HEPA-filtered vacuum that has a motorised head and electrostatic disposable bags — HDMs love living inside vacuum cleaners!

7. If changing sheets, vacuum your mattress immediately after getting out of bed, when mites are close to the surface.

8. Store seasonal items in space bags, removing air to kill HDMs.

9. Avoid bunk beds for allergy sufferers, especially the bottom bunk, where airflow is restricted and mites thrive.

You might not see them, but house dust mites are among the most common roommates in Australian homes. With a few smart changes to your bedroom environment, you can reclaim your space — and your sleep — from these microscopic freeloaders.