The creature living in your mattress right now
A standard double mattress in an Indian home can harbour between one and ten million dust mites at any given time. The figure comes from a 2018 review published in the Indian Journal of Allergy, Asthma and Immunology, which found that house dust mite sensitisation was present in 60 to 80 percent of allergic asthma patients studied across multiple Indian cities. The mites themselves, Dermatophagoides pteronyssinus and Dermatophagoides farinae are the two species most commonly found in Indian homes, do not bite and are not parasites. What they produce is the problem. Each mite sheds roughly 20 faecal particles per day, and it is these particles, along with fragments of their shed exoskeletons, that act as allergens. They are light enough to become airborne when bedding is shaken or a mattress is sat upon, and small enough to reach deep into the lungs.
