It lives in dark places and can make people sick.
It is also something most people who live in the desert don't expect to find hiding inside their home.
The culprit is black mold.
A Kingman woman and her family recently found an abundance of the fungus on, and inside, the walls of their home after years of constant unexplained stomachaches, headaches, sore throats and breathing problems, she said.
"I asked our health care provider if the problems could be caused by mold, because I had read an article about it," she said.
"But we were told, 'We don't have that here (in the desert).'"
The family made the discovery when they moved a large dresser in the bedroom and found a patch of black mold about four inches round on the wall.
The woman and her husband became concerned and decided to investigate further.
After cutting away a small section of the wall they found black mold growing inside.
They then removed the all the dry wall on one side of the room and found black mold growing in the bottom of the wall.
"When I was redoing the bathroom next to the bedroom, I removed a cabinet and found more black mold," she said.
The family, who has lived in the 40-year-old home for about 11 years, had a leaky roof about four years ago.
"It probably started then," she said.
"We had water coming down the walls, and had to replace the roof and the ceiling."
She added that an insurance investigator who recently visited the home told the family the problem is not as uncommon as people think in Mohave County, and can become quite serious.
"Once it is inside your house you have to treat it with a chemical to kill it," she said.
She was also told that in extreme cases a company that specializes in mold removal is called to the home.
Larry Webert, the acting manager of the environmental health division of the Mohave County Department of Health and Social Services, said black mold can occur when moisture becomes trapped in a dark place.
"A school in Lake Havasu City was found to have black mold," he said.
"It was a tremendous problem."
"In that case the mold was caused by a leaky roof letting moisture into the building," he said.
"Since then several people have called with mold in their homes."
Moisture from a leaky pipe, water heater, evaporative cooler or air conditioner can also cause black mold, Webert added.
"You can use chlorine bleach to kill it.
It depends on how severe it is," he said.
"But other times the dry wall has to be removed.
It can be a big expense."
Molds are simple, microscopic organisms found virtually everywhere.
If contamination in the home is extensive it can be a cause for concern.
When airborne mold spores are present in large numbers they can cause allergic reactions, asthma episodes, infections and other respiratory problems, according to the health department.
If moisture is available to allow mold to thrive and multiply, it can become a serious problem.
For some people, a relatively small number of mold spores can cause health problems.
For others, it may take many more.
Infants and children, the elderly and immune-compromised patients appear to be at a higher risk for adverse health effects caused by molds.
Some surfaces can be disinfected with a solution of one and half cups of bleach per gallon of water, but cleaning mold off damaged materials (when mold counts are typically 10 to 1000 times higher than background levels) can be hazardous to a person's health, according to the health department.
The health department recommends using a mask or respirator when cleaning moldy materials.
Residents concerned about mold in their homes may contact a company that conducts mold spore testing.
Other companies specialize in the removal of hazardous material abatement, according to the health department.