Color: Dark gray
Legs: Six
Shape: Small oval
Size: 1/4 of an inch
Antennae: Yes
Flight: Yes

House flies get their name from being the most common fly found around homes. Adult house flies can grow to one-quarter of an inch long and usually live between 15 and 25 days.

They are only able to feed on liquids but have the ability to turn many solid foods into a liquid for them to eat. House flies taste with their feet, which are 10 million times more sensitive to sugar than the human tongue.
House flies tend to stay within 1-2 miles of where they were born; however, they have been known to migrate up to 20 miles to find food.

These insects have been known to carry over 100 different kinds of disease-causing germs, which makes them very bad house guests.

Pests No Summer Picnic; Send Them Packing

“Filth flies” are aptly named. They breed in filth such as moist or decaying organic matter or excrement, and they feed by “spitting out” saliva and former stomach contents onto their intended next meal. After a few seconds, they suck up the fluid they spit out, along with anything it might have dissolved.

Not a pretty sight. But what’s worse is that they spread serious diseases.

Filth flies love to invade our homes during the warm summer months, along with other unwanted pests such as silverfish, millipedes and centipedes, honey bees, skunks and bats— although hopefully not all at once.

No, you don’t want them around to ruin an otherwise pleasant summer.

“These pests can make your fun in the sun a terrible memory,” says Mark Lacey, director of technical and field services for the National Pest Management Association (NPMA), a trade group representing professional pest control companies in the U.S. and around the world.
“They don’t really cause significant damage to your house or business, but will cause damage to your daily activities,” he adds. “For instance, it’s very easy for filth flies to transmit diseases to humans.”

Filth flies – there are about 200 species of them – have been proven to spread more than 65 kinds of human diseases, including leprosy, typhoid, E. coli, cholera, polio, TB, “Staph,” and several kinds of food poisoning.

Problems with humans arise when a fly feeds on some filth, such as dung or garbage, then a few seconds later lands on our plate or sandwich intent on eating the same morsel we plan to eat. Both the habit of regurgitating some of their stomach contents when they feed, and their hairy bodies, make it easy for filth flies to transmit pathogens to humans.

Lacey says summertime “panic calls” to pest control operators are not unusual due to honeybees or filth flies in a porch area just hours before guests are to arrive. Or the discovery of bats in the attic or a skunk or two under decks and in crawl spaces.

Sanitation and mechanical controls have the greatest long-term effect on reducing filth fly populations.

“As always,” Lacey advises, “homeowners and building managers should leave the control of pests to the professional pest control company. Call them at the first sign of a problem to avoid more difficult and costly control later.”

In an integrated pest management approach, the five basic steps taken for unwanted pests are: inspection, identification, the establishment of threshold levels, the employment of two or more control measures, and the evaluation of effectiveness.

Biologists have identified 925 species of the scary-looking bat, one quarter of all known mammal species. The oldest bat fossils are 50 million years old, and paleontologists assume bats had been flying around for a few million years before that.

The bat most Americans probably know best in the summer is the little brown bat, which roosts in attics and barns and prowls for insects at twilight. Although their eyesight is better than most people think, bats routinely depend on their sonar-like location system to hunt flying insects.

Medical concerns about bats are mainly the very small, but real, risk of rabies, which is found in less than 1% of the bat population.
The main situation in which humans are at any risk are when the bat is either sick or injured and falls down within a human occupied area or at least to within a human’s reach.

Control of bats, within the continental U.S. and similar temperate regions, is mainly a combination of removal followed by exclusion. As with other unwanted summertime pests, if you have a bat problem, contact your local licensed and professionally trained pest control professional.
Far less complex than bats, silverfish and their close relatives, firebrats, are small, wingless tear-drop-shaped insects generally covered with, respectively, grayish or brownish scales.

They hide in cracks during the daytime and become active after dark. They survive best in high relative humidity and at the higher temperatures of summer. Most feed on starches, sugars, and proteins they can get from book bindings, glazed paper, or similar sources, including dead insects.
In the home, they may severely damage older books, papers, or other sweet or starchy materials in warm, moist, dark areas. They are often introduced into a home within cardboard or other paper products.

Another summer pest, millipedes, are sometimes called “thousand leggers” because they have 30 to 90 pairs of legs. They’re not really insects, but they can be pests. Their close cousins, centipedes, have less legs. Most common centipedes rarely grow beyond a few inches but can grow up to six inches, which will scare young children and adults alike. Millipedes can grow up to about four inches long. You don’t want them around either.
While honey bees are among the most beneficial insects, they can be pests when they end up in our living space after they build hives in walls or in nearby bushes.

Problem is, honey bees can sting, and some people react violently. Worse, the much-publicized Africanized honey bees, or “killer bees,” have now reached warm areas of the country and are moving further north each year.

By midsummer, honey bees reach very high populations. Interiors should not be fogged if honey bees are found because robber bees may reoccupy the hive, thus perpetuating the bee problem. Instead, a pest control company should be called to alleviate the problem with maximum care and minimal risk to the occupants.


Mountain Pest Control, providing quality pest management services, locally owned and operated since 1977

Aspen to Glenwood Springs, Rifle, Silt, New Castle

3758 Highway 82,
Glenwood Springs, CO 81601

(970) 945-5942 Phone
(970) 945-1305 Fax

Mon – Fri: 8AM to 5PM MT

Steamboat Springs

Summit County, Breckenridge, Frisco, Silverthorne, Dillon, Keystone


Flies are very difficult to manage and eradicate on your own. If you need help removing Flies from your home or business, contact Mountain Pest Control, we’re here to help.