You know something is biting you. You have checked for bed bugs and come up empty. You have vacuumed, washed every piece of bedding, and still wake up with red, itchy welts. The culprit may be smaller than you imagine, and it may have arrived via a neighbor you never expected — a rat, a bird, or even a nest hidden in your walls.
Before reaching for any product, the most important step is making sure you are actually dealing with mites. Unexplained skin irritation has multiple possible causes — environmental irritants, other pests, medication reactions, or medical conditions can all produce similar symptoms. Confirming the cause first is not just good practice, it is the only way to solve the right problem. We will come back to this at the end.
Biting mites are real, they are more common than most people realize, and they are genuinely difficult to detect. Here is what the science says about what causes them and what to do about it.
Meet the Most Common Culprits
Andrew M. Sutherland, Ph.D., BCE, is a UC Cooperative Extension Urban IPM Advisor and one of the leading experts on biting mites in structures. In his article Detecting and Controlling Biting Mites Within Structures, published by UC ANR, he identifies the three species most likely to be responsible for unexplained bites indoors:
The tropical rat mite (Ornithonyssus bacoti) is the most common offender in California, typically associated with roof rats nesting in wall voids, attics, or crawl spaces. The northern fowl mite (Ornithonyssus sylviarum) lives in the nests of pigeons, starlings, sparrows, and swallows. The chicken mite or red mite (Dermanyssus gallinae) is less common but increasingly relevant as backyard poultry ownership has grown.
All three species share one critical trait: they are nest parasites that feed on the blood of their primary hosts. They bite humans only when those hosts are no longer available — removed by pest control, migrated away, or no longer visiting the nesting site.
Why the Mites Come After You
This is the part that surprises most people. Dr. Sutherland explains that successful rodent control programs can actually trigger mite activity in living spaces. Remove the rats — and suddenly hundreds of hungry mites begin wandering in search of a new blood source. If the rats were nesting behind your walls, those mites know exactly which direction the warmth is coming from.
In his research, Dr. Sutherland is clear that biting mites found indoors are nest parasites of other animals — most commonly rodents or birds living in or near the structure. That distinction matters, because it points directly to where any lasting solution has to start.
A similar situation plays out when migratory birds abandon nests built in window alcoves, eaves, or anywhere adjacent to living spaces. The mites do not leave with the birds — they stay behind and start looking for their next meal.
Tropical rat mites are also known to travel impressive distances, moving along pipes, utility wires, tree branches, fencing, and the exterior of structures. The source of your problem may not even be inside your home.
How to Know If You Are Dealing With Mites
Detection is the hardest part. Mites are tiny — about 1/16 of an inch or smaller — and often invisible to the naked eye unless you know what to look for. Before feeding, they appear yellowish or whitish. After a blood meal, they turn dark red.
Dr. Sutherland recommends a few practical detection methods: sticky traps or glue boards placed at floor-to-wall junctions and in corners, examined with a 10x hand lens. Double-sided tape applied to furniture legs or walls near where bites occur can also catch wandering mites. These methods may not give you a confirmed species ID, but they can confirm that mites are present and responsible for the bites.
For positive species identification, a captured live specimen preserved in rubbing alcohol (at least 70%) is needed. Some county vector control programs can assist with identification.
The Right Approach to Treatment
Dr. Sutherland is clear that the primary management strategy is removing the host — the rats, birds, or other animals whose nests are driving the mite population. Without addressing the source, any surface treatment is temporary.
Once the host is removed or controlled, the mite population will decline on its own over time. The challenge is that mites can survive without a primary host for an extended period, continuing to bite humans and pets while they search for a new source.
That is where a plant-based, contact-kill solution becomes valuable. Dr. Sutherland notes in his research that mites, as soft-bodied arthropods, are vulnerable to soaps and oils, and that some pest management professionals have had success with essential oil products.
Where Premo Guard Fits In
Premo Guard Mite Killer Spray is a plant-based, enzyme-based formula designed for use on surfaces where mites are active — bedding, mattresses, furniture, carpets, and more. It is child and pet friendly, leaves no chemical residue, and is free of synthetic pesticides.
The key: use it during that transition window while the mite population is still active but declining. Treat surfaces thoroughly in the areas where bites are occurring. Focus especially on the path between the likely mite source (walls, ceilings, floor-to-wall junctions) and the areas where you spend time.
Laundry is often overlooked — but your bedding, clothing, and soft furnishings can harbor mites and their eggs. Premo Guard Laundry Additive is an enzyme-based formula that works in your regular wash cycle to eliminate mites from fabric. Adding it to your laundry routine during a mite situation closes a gap that surface sprays alone cannot reach.
Used together — Mite Killer on surfaces and Laundry Additive on fabrics — you cover both sides of the problem while you work on eliminating the host.
One More Thing Worth Knowing
As we mentioned at the top: mites are not always the answer. Sometimes they cannot be detected even when symptoms persist. Sometimes the source is never identified. And sometimes the cause turns out to be something else entirely — an environmental irritant, a medication reaction, or a medical condition worth discussing with a doctor.
Dr. Sutherland's UC IPM publication Itching & Infestation: What's Attacking Me? is one of the most thorough resources available for anyone trying to work through unexplained skin symptoms. We recommend starting there if you have not already.
When mites are confirmed, Premo Guard is here to help. When they are not — the right answer is still the right answer.
Resources
Detecting and Controlling Biting Mites Within Structures — Dr. Andrew Sutherland, UC ANR
Itching & Infestation: What's Attacking Me? — UC IPM
Preventing and Monitoring for Biting Mites — Video — Dr. Andrew Sutherland, UC IPM
Attack of the Mystery Mites — Video Series — Dr. Andrew Sutherland, UC IPM
About Premo Guard: Premo Guard is a natural, plant-based pest control brand offering enzyme-based and essential oil-based solutions for mites, bed bugs, laundry, poultry, and pets. All products are child and pet friendly and free of synthetic pesticides.
