Spider mites do not bite humans under any circumstances, despite their name and appearance as tiny arachnids. These microscopic relatives of spiders are plant pests, measuring less than 1/50th of an inch. Their sole focus is the plant life in your home or garden, where they can cause significant damage. Their specific biology explains why they pose no direct threat to human skin.
Why Spider Mites Do Not Bite People
The reason spider mites cannot bite people is directly related to their specialized feeding apparatus and diet. Spider mites are herbivores with mouthparts adapted exclusively for a piercing-sucking feeding mechanism on plant tissue. These pests use stylets, which are needle-like mouthparts, to penetrate the cell walls of leaves and extract the internal contents.
Their diet consists of chlorophyll and other cell contents found only within the leaf mesophyll. Human skin is far too thick and tough for these delicate stylets to penetrate effectively. Human tissue does not contain the plant cells necessary to sustain the mite, meaning they have no biological motivation to feed on people.
Although a spider mite infestation might lead to mild, indirect skin irritation from contact with their fine silk webbing or microscopic bodies, this is not a bite. Any minor sensitivity is typically resolved with simple washing.
Other Household Pests That Cause Skin Irritation
When a person experiences unexplained skin irritation or what appears to be tiny bites, the cause is rarely a spider mite. The symptoms are often the result of other minuscule household arthropods that interact with human hosts. Bird mites and rodent mites are common culprits; they normally feed on their respective hosts but will disperse into living spaces and bite humans if their primary host dies or leaves a nest nearby.
Another source of irritation often mistaken for bites is the tiny hairs shed by the larvae of carpet beetles. These microscopic bristles can cause an allergic reaction, resulting in an itchy, rash-like dermatitis. Dust mites, which are present in every home, do not bite but their waste and shed body parts are a major source of indoor allergens, triggering sneezing, coughing, or itchy eyes in sensitive individuals.
Chiggers, which are the larvae of certain outdoor mites, can attach to skin and cause extremely itchy, raised red welts. This occurs particularly after being outside in grassy areas.
Identifying and Controlling Spider Mite Infestations
Since spider mites do not bite, the true concern is the damage they inflict on plants. The first signs of an infestation are typically light-colored stippling, which are tiny yellow or white pinprick dots on the leaves. This is a result of the mites destroying the plant’s chlorophyll-containing cells.
As an infestation progresses, you may notice fine, silky webbing stretched across the leaves and stems. To confirm the presence of mites, strike an affected branch over a piece of white paper; the dislodged mites will look like specks that slowly move across the surface.
Control often begins with non-chemical methods, such as physically dislodging the mites with a strong jet of water. Increasing the humidity around indoor plants can make the environment less favorable for spider mites, as they thrive in hot, dry conditions.
For more severe cases, horticultural oils or insecticidal soaps can be applied. Ensure thorough coverage, particularly on the undersides of leaves where the mites congregate. These “soft pesticides” work by contact and are generally more effective against mites than common insecticides.