Mites are small pests barely visible to the naked eye. In
California, the most common biting mites include the tropical rat
mite, the northern fowl mite, and the chicken mite. They feed on
rodents, birds, and fowl and occasionally infest homes and bite
humans once their host has left the area.
Some mite species may also be found outdoors. These mites do not
typically infest homes, but people may be bitten while spending
time outdoors, especially in tall grass or brush.
Detecting Mite Infestations Indoors
Unlike fleas, which tend to bite on the ankles and lower legs,
mites may bite anywhere on the body. Bites may occur where
clothes constrict the body such as the waistline and under the
arms. They may cause painful or itchy skin irritation on all or
some family members.
Mites are usually most active at night. When searching for mites,
a flashlight should be used to examine walls near heat sources
such as hot water pipes, heating ducts, electrical
fixtures, and around bedding. Mites usually retreat
to dark spaces such as cracks and crevices between
feedings. You may also want to try using a sticky trap (such as
those sold for bedbug detection) to try to collect a sample.
The first thing you should do if you have mites is eliminate
their host. Check your
property carefully for rodent infestation, and resolve any
issues you find. Eliminate any bird nests under eaves and in
attics. Be thorough! It will be impossible to eliminate mites if
their animal host is still living in your home.
Mites can live up to six weeks without a blood meal, but will
begin searching for a new host immediately. You may notice more
bites once you have eliminated the animal that is causing the
problem. If this happens, you should contact a professional pest
control operator (PCO) to treat for mites.
San Mateo County Mosquito and Vector Control District
provides identification of suspected mites and other
insect/pest specimens. Please bring a sample to the District
office for identification. Home inspections for bird or
rodent infestation are also available. Schedule a
service request by phone or online. All District services are
provided at no additional fee to county residents.
Mystery Bug Bites and Your Health
Mites are not truly invisible, but may be very difficult to see
because they are so small. However, if you continue to experience
bites without finding any mites or other pests, you should
consider other explanations.
A feeling that something is crawling on or biting the skin may be
a symptom of a serious medical condition. You should consult a
medical provider before pursuing additional pest control measures
on your own.
Mites are probably one of the most common insects on the earth
and the vast majority of them have not been described yet. While
the majority of them are harmless to humans and even helpful to
us, there are several that are found in San Mateo County that can
be a right nuisance. Most of these species are unable to invade
your home without their host (usually rats or wild birds) but
once there, they may bite humans if they reach a large population
size or their host dies. Below are some of the most common biting
mites in San Mateo County.