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Pest Facts


Pavement Ant

Probably the most common ant in structures, the pavement ant, is so named because it excavates an underground nest and pushes the soil into conical mounds along rocks, concrete slabs, sidewalks and driveways. Nests also can be found in logs, mulch, wall and floor voids, and insulation. Pavement ants are dark brown-black and about 1/6-inch long. They forage 30 feet or more from their nest in search of a variety of foods, including grease and oils, seeds, sweets and honeydew (the sugary waste of aphids). They are often seen indoors after heavy rain drenches their underground territories.


Odorous House Ant

This 1/8-inch long, brownish-black ant can be confused with the pavement ant, until the odorous house ant is crushed, releasing an odor like rotten coconut. In recent years it has become an increasingly common household invader. Nests are found under rocks, boards and other debris, and in floor and wall voids. These ants will move indoors during rains and in the fall. They feed on sweets, honeydew, plant and fruit juices, meat and dairy products.


Carpenter Ants


Illinois ’ largest ants are known as carpenter ants because they nest in wood. Nests consist of numerous tunnels chewed in logs, stumps, tree trunks, firewood, decks and porches, window and door frames, wall voids and foam insulation. The ants expel piles of sawdust, dead ants and parts of dead insects from the nest and these can help inspectors determine the nest’s location. Indoor nests are usually “satellite” nests connected to the colony’s main nest outdoors. Satellite nests are often established in wood where moisture problems exist (e.g., around leaking pipes, inadequately sealed window frames and roof leaks). The common black carpenter ant (C. pennsylvanicus) is a dull black ant with workers of various sizes up to ¾-inch long. Other species are black or dark reddish-brown. They do not eat wood but forage for human foods, including sweets, meats and grease, as well as honeydew, and live or dead insects


Pharaoh Ant

The tiny (1/12-inch) pharaoh ant is yellow to reddish-brown. It is nearly identical to the thief ant (Solenopsis molesta). However, the pharaoh has an “antennal club” consisting of three expanded segments on the end of its antenna, while the thief ant has a two-segmented antennal club. Pharaoh ants nest in voids in floors, walls and ceilings. They often infest large buildings. In hospitals, these ants pose a health risk because they can carry infectious bacteria from the warm, moist areas they inhabit, to intravenous fluids, blood and wounds. The pharaoh ant also presents a problem for pest management. The colonies of this ant do not spread by swarming, but instead by “budding,” breaking apart and establishing sub-colonies in new locations. This process can be triggered when the colony is stressed by the application of repellent liquid or dust pesticides. Colonies can be very large, some containing more than 100,000 ants.


Wolf Spider


Any large, hairy spider in the eastern half of the United States is more than likely a wolf spider. These spiders may grow to have bodies 1 inch long with a leg span of 2 or more inches. They are generally black or gray in color, but sometimes reddish, brown or tan. Two of their eight eyes are often larger than the rest.

Wolf spiders are active hunters that search for prey day or night. Some burrow and others rest in silken retreats beneath rocks, logs and vegetation. Females attach their egg sacs to their spinnerets and carry the egg sacs and spiderlings around after they hatch.

As with other large spiders, the bite of a wolf spider is likely to be felt but is not considered dangerous. Bites from these and other large spiders are not common.  


Brown Recluse Spider

The brown recluse is a small-bodied, medium-sized spider whose outstretched legs span little more than the diameter of a quarter. It is almost uniformly brown and without banded legs or other prominent markings – except for the dark violin-shaped mark on its cephalothorax, just behind its eyes. Unlike most spiders, the brown recluse has six eyes arranged in three pairs, instead of the usual eight.

Because brown recluse spend much of the day hiding inside furniture, boxes and stored goods, they are easily transported with these items. This and other characteristics allow them to establish themselves in new locations. They are long lived, can survive for many months without feeding, and females need mate only once to produce offspring throughout their lives. So it takes only one, mated female to start an infestation. Once established, they are difficult to control.

Yet even in heavily infested structures, brown recluse are indeed reclusive, not aggressive, and bites rarely occur. Nevertheless, physicians often misdiagnose many unrelated injuries as “brown recluse bites.” When they do occur, bites are rarely as serious as they have been portrayed. Some bites produce only localized redness and swelling. Severe necrosis probably occurs in less than 10 percent of cases, and may result more from bacterial infection of the wound rather than reaction to the spider’s venom.


Cellar Spiders


These spiders are sometimes called “daddy-longlegs” because of their long, delicate legs. Their tiny bodies are not more than ¼-inch long. Cellar spiders are most often seen hanging upside down in sheet-like or irregularly-shaped webs in corners near the ceiling or floor. The webs can quickly accumulate and become unsightly nuisances in cellars, basements or commercial buildings such as warehouses.


Yellow Sac Spider 


Yellow sac spiders (Chiracanthium inclusum and C. mildei) are the most common species indoors. Their bodies are about ¼-inch long and, including legs, the spiders are less than the size of a quarter. They are a pale yellow color.
Yellow sac spiders are fast-running, nocturnal hunters that can be found from floor to ceiling in structures and will drop on a line of silk when disturbed. They also are common outdoors where they live in vegetation and often enter homes as temperatures drop in fall.

Because they are common indoors and may bite instinctively when touched, yellow sac spider bites may be more common than bites from any other spider in the United States. At least some of the injuries listed by medical personnel and poison control centers as “spider bites” or “brown recluse bites” are those of the yellow sac spider. Reactions to sac spider bites may vary. The bite is often felt as a sharp pain. Localized redness and swelling typically develop and dissipate within two hours.


German Cockroach


The German cockroach (Blatella germanica) is by far the most common roach found in kitchens. It is a half-inch long, bronze-colored insect that avoids light and hides in cracks and crevices. Adults and older nymphs have two black stripes on the back just behind the head. 

German cockroaches spend about 75 percent of their lives in hiding. Enabled by a body that’s smaller than other species, the ability and inclination to hide in tiny spaces is one reason why the German cockroach has been so successful at living with humans. Coming out of hiding to feed or to mate can be dangerous, so it’s usually done in darkness. When the roaches leave their hiding spots, they only go as far as they need to find food and mates. Their hiding places are usually within 10 feet of their food source. 

Another characteristic lending success to the German cockroach is its rapid reproduction. Unlike other roaches that drop their egg capsules days before the eggs hatch, the female German roach goes into hiding, holding the egg capsule on the end of her abdomen until the eggs are about 24 hours from hatching. This method of protecting the eggs, coupled with the relatively large numbers (30 to 48) of eggs per capsule, allows German cockroach populations to build quickly, such that about 80 percent of roaches in a growing population are nymphs. 

The German cockroach prefers to live close to its own kind. Prime hiding places can be occupied by many roaches. Large numbers can be found clustering together under stoves, refrigerators and dishwashers, and in wall and cabinet voids. Roaches defecate in such places, leaving dark speckling that contains pheromones – scent signals that mark a surface as a “fecal focal point” where roaches will gather.


Paper Wasps


Paper wasps are perhaps the most common wasps around structures. They are also known as “umbrella wasps” because their nests look like umbrellas hanging upside-down from eaves and overhangs. Common species include the northern paper wasp (P. fuscatus), a black to reddish-brown wasp up to ¾-inch long, and the European paper wasp (P. dominula) which is black and yellow, resembling a yellowjacket. A paper wasp nest is a single comb of hexagonal cells made of a papery material the wasps form by chewing wood and mixing it with saliva. Larger nests can harbor up to 75 paper wasps including larvae and pupae developing within the cells. To feed the larvae, paper wasps capture insects, especially caterpillars. Late in the year, colonies of paper wasps, yellowjackets and hornets produce new queens that abandon the nest (it will not be reused) and seek shelter for winter. Many find their way into structures and are later seen crawling sluggishly across the floor when temperatures rise in late winter or early spring.


Oriental Cockroach

The Oriental cockroach (Blatta orientalis) is the so-called “waterbug” of basements, crawlspaces and garages. It lives in cooler habitats with plenty of moisture – even outdoors around foundations in leaves and mulch where it can survive temperate winters. As a result, the Oriental cockroach’s development is slower. They require an average of 18 months to progress from egg to adult, while the German cockroach averages only two months to adulthood. In addition, the Oriental’s egg case contains 16 eggs, compared to the German’s 30 to 48 eggs per case. After being detached from the female, eggs inside the Oriental roach’s egg case require an average of two months to hatch.

Oriental cockroaches also differ in appearance. Newly hatched nymphs are brown and become blackish as they grow. Adults are up to 1 ¼ inches long with wide, flat bodies and no distinguishing markings. Males have wings that cover about half of the abdomen and females have only wing stubs; neither sex can fly. 

American Cockroach


The American cockroach (Periplaneta americana) is a large species, up to 2 inches long. It is reddish brown, but lighter around the edges of the thorax. Adults have wings extending to the end of the body. They can fly in temperatures above 85 F. 

American cockroaches are less common in homes than German cockroaches. They prefer sewers and boiler rooms, basements and steam tunnels in commercial establishments, especially where food is processed or prepared.

American cockroaches develop much slower than German cockroaches. The American’s egg case contains 14 eggs to 16 eggs. Females deposit them, often near food sources, where the eggs typically hatch in about 45 days. Average time from egg to adult is about 15 months. Nevertheless, large populations can develop under favorable conditions. 


Bald-faced Hornet


The so-called bald-faced hornet (Dolichovespula maculata), about ¾-inch long, black and white, with white face, is actually a larger yellowjacket species. Its nest is the familiar basketball-size papery oval hanging from tree limbs and sometimes structures. Colonies are relatively small, containing up to 700 wasps. An even larger wasp is the European hornet(Vespa crabro). This is a true hornet, more than an inch long and reddish brown in color with dull orange stripes. Nests occur in trees and in attics and wall voids of structures near forested areas.


Carpenter Bee

This bee is a bumble bee look-alike that has a shiny, all-black abdomen, whereas the bumble bee’s abdomen is fuzzy, black and yellow. Unlike bumble bees, carpenter bees are solitary. Females chew ½-inch diameter holes in wood and bore tunnels that run several inches into the wood. Inside, eggs are laid and the resulting larvae develop on a mixture of pollen and nectar. Males guard the nest by buzzing intruders, but their defense is a bluff: male bees cannot sting.


Mud Dauber Wasp


Mud dauber wasps are named for their habit of constructing tubular nests of mud plastered on the exterior surfaces of structures. Inside the nest, these wasps place spiders they have paralyzed by stinging, as food for their larvae. Mud daubers are solitary wasps about ¾-inch long. Our common mud dauber (S. caementarium) is brownish-black with yellow markings. Its nests are about 2 inches long. Organ pipe mud daubers(Tropoxylon spp.) are black and construct nests that can be a foot long and resemble the pipes of a pipe organ. The blue mud dauber (C. californicum) is a shiny, dark blue wasp that lays its eggs in the nests of other mud daubers.


Bumble Bee

The familiar buzzing, fuzzy yellow and black striped bumble bee is unmistakable. Up to 200, ½- to 1-inch long bumble bees inhabit nests in old rodent burrows, under porches and in wall voids.

Brown-banded Cockroach


This cockroach is sometimes encountered indoors, but it prefers higher temperatures (about 80 F) than the much more common German cockroach. It loves the warmth of electronics, motor housings, light fixtures, and ceilings. When German cockroaches are found in nonfood areas (such as bedrooms), this may indicate a heavy infestation, lack of hiding places, or use of a repellent pesticide – but such harboring in nonfood areas is typical of the brownbanded roach. 

Brownbanded cockroaches (Supella longipalpa) are slightly smaller than German cockroaches and more colorful. Males are a golden orange color with a broad band of dark brown. They can fly, with wings that cover their abdomens. Females are darker overall, with lighter bands on the abdomen. They have shorter wings and cannot fly. Nymphs are dark with cream-colored bands behind the head, and are golden orange over much of the abdomen. Nymphs and adults may jump when disturbed. 


Yellow Jacket

More people are stung by yellowjackets than any other type of wasp or bee. Notoriously aggressive, the yellowjacket’s shiny yellow and black striped abdomen is an unmistakable warning. Often mistakenly called “bees,” yellowjackets are in fact wasps. They construct paper nests up to several feet across that contain combs arranged like the floors of a building covered by a papery envelope. Up to 3,000 (many more in warmer states) wasps can be present in the yellowjacket colony. Nests of the Eastern yellowjacket (Vespula maculifrons) are located in the ground, while the German yellowjacket (Paravespula germanica) nests in cavities including crawlspaces, attics and wall voids. Adults consume nectar and sweets, but feed the larvae on captured insects. When temperatures cool in late summer, yellowjacket numbers peak just as their insect food supply begins to decline. They scavenge more aggressively at this time, taking food from trash containers and picnickers. When disturbed, some yellowjackets sting repeatedly, while others sting and lose their stingers as do honey bees.


American Dog Tick


One of the most frequently encountered ticks is the American dog tick, also sometimes known as the wood tick. The larvae and nymphs feed on small warm-blooded animals such as mice and birds. The adult American dog tick will feed on humans and medium to large mammals such as raccoons and dogs.

Unfed males and females are reddish-brown and about 3/16-inch long. Females have a large silver-colored spot behind the head and will become ½-inch long after feeding or about the size of a small grape. Males have fine silver lines on the back and do not get much larger after feeding. Males are sometimes mistaken for other species of ticks because they appear so different from the female.

In Illinois, the adults are most active in April, May and June. By September, the adults are inactive and are rarely observed. The American dog tick can transmit Rocky Mountain spotted fevertularemia and possibly ehrlichiosis to humans.


Lone Star Tick

The lone star tick is primarily found in the southern half of Illinois, although it can occasionally be found further north. Larvae, nymphs and adults will feed on a variety of warm-blooded hosts, including people. The larva is very tiny, only a little larger than the period at the end of this sentence. The nymph, the most common stage found on people, is about pinhead-sized. Adults are about 1/8-inch long and brown. The adult female has a white spot in the middle of her back. Because they are so similar in size, the lone star tick is sometimes misidentified by laypersons as the blacklegged / deer tick (see below).

The lone star tick is most active from April through the end of July. Although it can transmit Rocky Mountain spotted fever, the lone star tick is not as likely to transmit the disease as the American dog tick. This tick also may transmit tularemia and ehrlichiosis to humans. The lone star tick is not believed to transmit the bacteria that causes Lyme disease (Borrelia burgdorferi), but may be associated with a related bacteria species that has not been completely identified.


Black Legged (Deer) Tick


All three active stages of the blacklegged / deer tick will feed on a variety of hosts including people. After the eggs hatch in the spring, the very tiny larvae feed primarily on white-footed mice or other small mammals. The following spring, the larvae molt into pinhead-sized, brown nymphs that will feed on mice, larger warm-blooded animals and people. In the fall, they molt into adults that feed primarily on deer, with the females laying eggs the following spring. Adults are reddish-brown and about 1/8-inch long (or about one-half the size of the more familiar female American dog tick).

These ticks are found in wooded areas along trails. The larvae and nymphs are active in the spring and early summer; adults may be active in both the spring and fall. The blacklegged / deer tick can transmit Lyme disease, babesiosis and possibly ehrlichiosis to humans.

The deer tick has been found sporadically in many Illinois counties. However, in recent years it has been common only in limited areas, mostly in northern Illinois (Geographic distribution by county). Additionally, Illinois residents may encounter the deer tick during trips to Michigan, Minnesota, Wisconsin or the northeastern United States where it is very common in some areas.


Brown Dog Tick

The brown dog tick (also known as the kennel tick) is found through most of the United States This tick feeds on dogs, but rarely bites people. Unlike the other species of ticks, its life cycle allows it to survive and develop indoors. The brown dog tick is found primarily in kennels or homes with dogs where it may be found hiding in cracks, behind radiators, under rugs and furniture, and on draperies and walls.

The adult is reddish-brown and about 1/8-inch long, and usually attaches around the ears or between the toes of a dog to feed. After feeding, a female may engorge to ½-inch long. She then drops off the dog and crawls into a hiding place where she may lay as many as 3,000 eggs. This tick is tropical in origin and does not survive Illinois winters outdoors. The brown dog tick is not an important carrier of human disease.



Two different kinds of mosquitoes plague Illinoisans. Floodwater (temporary pool) mosquitoes deposit their eggs singly in low-lying areas that will be flooded later. Under normal summer temperatures, large numbers of biting mosquitoes will emerge about two weeks after heavy rains and can be a major nuisance problem for several weeks.

The most common of these in Illinois is the inland floodwater mosquito. A vicious biter, this mosquito will commonly fly 10 or more miles from where they hatch,
particularly along prevailing winds. Floodwater mosquitoes have not been significant disease carriers in Illinois.

Vector mosquitoes carry diseases and lay their eggs in stagnant ditches and sewage treatment ponds or water in treeholes, old tires, clogged gutters, old tin cans and anything else that will hold water. Eggs are laid on or just above the water surface, where they usually hatch within two to three days. Two of the more common vector mosquitoes in Illinois are the Culex, or house mosquito, and the tree-hole mosquito. Neither migrates long distances.

Another disease-carrying mosquito is the Asian tiger mosquito, which arrived in the United States in 1985 in old tires. An aggressive day-biting mosquito, it breeds in large numbers in water-filled artificial containers.



The dark speck that suddenly appears when you walk across the carpet, then disappears, is likely a flea. It’s a bloodsucker, reddish-brown, about one-eighth of an inch long. Using a magnifying glass, you’d see the flea’s body is flattened from side-to-side and it has long claws on its legs – both are adaptations for traveling between hair shafts. The flea also has spines on its mouth, legs and back to help prevent it from being groomed off.

Nevertheless, a dog will probably pick off many of the cat fleas it hosts. Cat fleas(Ctenocephalides felis) are more common on cats, dogs and humans than dog fleas(Ctenocephalides canis) and human fleas (Pulex irritans). Each has its preferred hosts. The human flea prefers the blood of humans and pigs. Cat and dog fleas prefer cats and dogs, though children can become infested when pets sleep or rest on the same bed. Cat and dog fleas also will infest certain types of wild carnivores, including opossums and raccoons, but not squirrels, rats or mice. While these two species do not carry human diseases, they can carry tapeworms (Dipylidium caninum) that infect dogs.

Other flea species occasionally encountered by humans include the oriental rat flea(Xenopsylla cheopis) and the northern rat flea (Nosopsyllus fasciatus). These fleas live on Norway rats and roof rats, and are capable of transmitting plague and murine typhus to humans.



“Mite” is a term commonly used to refer to a group of insect-like organisms, some of which bite or cause irritation to humans. While some mites parasitize animals, including man, others are scavengers, some feed on plants, and many prey on insects and other arthropods. In fact, there are nearly as many different types of mites as there are insects. Like their relatives, the ticks, mites pass through four stages of development: egg to larva to nymph to adult. All stages have eight legs except the six-legged larva.

Most mites never come in contact with humans, but some that do can affect a person’s health. Yet, in many situations where mites or other “invisible” arthropods are believed to be biting or “attacking” people, no causative organism is present. The irritation may be real or imagined: real, due to mechanical, chemical or other inanimate irritants, or imagined due to a psychological disorder.

While mites rarely transmit disease to humans in the United States, they definitely impact health in ways that range from simply being a nuisance when they enter homes in large numbers, to inflicting severe skin irritation that can cause intense itching. 


Bed Bugs

The bed bug (Cimex lectularius) has been a parasite of humans throughout written history. Its adaptation to humans is so complete that its bite is not noticed until well after the bug leaves its victim, if it is noticed at all. Attracted by the warmth of our bodies and the carbon dioxide we exhale, bed bugs emerge usually at night from hiding places, seeking human blood. Bed bugs can survive more than a year without feeding, but most adults and nymphs probably do not live more than six months without a meal. This ability lets them wait for transient hosts that periodically inhabit camp cabins, apartments and temporary housing. It also helps them survive transportation. Today, bed bugs “hitchhike” more easily than ever, via public transportation and luggage, and in secondhand furniture, mattresses, bedding and clothing. In multi-unit buildings, bed bug infestations that are not adequately attended to often spread between units with or without human help, making eradication much more difficult and costly.

insects can be quite the nuisance. Whether its getting in our homes and businesses to chewing up wood in buildings  compromising a structures integrity. insect specious such as termites, carpenter ants, and carpenter bees although very beneficial in nature as they break down fallen timber can also cause serious damage to homes and other structures. Insects such as pavement ants can displace sand and soil causing pavement slabs to shift or in worst cases even crack. On the other hand        Roaches and other species of crawlers don't necessarily cause any serious structural damage, they can be a health hazard. Roaches have many negative consequences for human health because certain proteins (called allergens) found in cockroach feces, saliva and body parts can cause allergic reactions or trigger asthma symptoms, especially in children. And then we have the stinging and biting insects such as spiders and wasps/hornets. These guys wont typically cause any structural damage around homes and other buildings but can be a health hazard to minors or those with compromised health. 

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