Ants have been a major invader of homes and businesses for years.  However, increases in residential and commercial development in the last decade have contributed to the increase in the number of structures being infested by these problem pests. Ants can be difficult to control, but not impossible.  Here are a few things you should know about ants behavior that can lead to headaches for your home or business:

Entry: Ants can enter through even the tiniest cracks, seeking sweet or greasy substances in the kitchen pantry or storeroom areas.  (Some ants prefer sugars some prefer proteins and they will even change their mind depending on the seasons)

Scent trails: Ants leave an invisible chemical trail known as pheromones for others to follow once they locate the food source.

Nest locations: They can nest just about anywhere in and around your house; in lawns, walls, stumps, even under foundations.

Colony size: Can number from 300,000 to 500,000, and whole colonies can uproot and relocate quickly when threatened.

Nature's way of protecting the colony: With comparative freedom from natural enemies, a colony can live a relatively long lifetime. Worker ants may live seven years, and the queen may live as long as 15 years.

Do-it-yourself ineffectiveness: Most do-it-yourself approaches only kill the ants you see, whereas a truly effective treatment will penetrate and destroy their nest to prevent them from returning. Also, home remedies don't account for the fact that different kinds of ant infestations require different treatments.

Rodents - Here is what you should know about these pests:

RATS

Difficult to control: Rats are instinctively wary of traps and bait, and colonize in attics, burrows, under concrete and porches, in wall voids and other hard to reach places.

Disease: Rats can harbor and transmit a number of serious diseases. They can also introduce disease-carrying parasites such as fleas, lice and ticks into your home.

MICE

Access: They invade your home seeking food, water and warmth. One pair of mice can produce 200 offspring in four months.
Conamination: Each mouse can contaminate ten times more food than it eats.

There's good news and bad news about Roaches.

The good news: Roaches are no longer the most common and difficult-to-control pest, according to Cindy Mannes, Director of Public Affairs for the National Pest Management Association. Thanks to better sanitation practices by homeowners, they've moved to the number-three spot.

The bad news: Roaches are active at night, so if you see roaches in your kitchen during the daylight hours, you may have a really bad infestation.

Roaches don't do structural damage to homes, but they do spread germs. "Cockroach allergens have also been linked to triggering children's asthma," says Mannes. Cockroach prevention includes sealing all holes and cracks that provide access to your home from the outside. Make sure to do this in the basement as well as the crawlspace. Keeping food sources scarce will help, though it's a tough task because this bug dines on everything from garbage to wallpaper paste.

Cimicidae (or sometimes bedbugs) are small parasitic insects. The most common type is Cimex lectularius. The term usually refers to species that prefer to feed on human blood. All insects in this family live by feeding exclusively on the blood of warm-blooded animals.
A number of health effects may occur due to bed bugs, including skin rashes, psychological effects, and allergic symptoms. Diagnosis involves both finding bed bugs and the occurrence of compatible symptoms. Treatment is otherwise symptomatic.
In the developed world, bed bugs were largely eradicated as pests in the early 1940s, but have increased in prevalence since about 1995. Because infestation of human habitats has been on the increase, bed bug bites and related conditions have been on the rise as well. The exact causes of this resurgence remain unclear; it is variously ascribed to greater foreign travel, more frequent exchange of second-hand furnishings among homes, a greater focus on control of other pests resulting in neglect of bed bug countermeasures, and increasing resistance to pesticides. Bed bugs have been known as human parasites for thousands of years.
The name "bed bug" is derived from the insect's preferred habitat of houses and especially beds or other areas where people sleep. Bed bugs, though not strictly nocturnal, are mainly active at night and are capable of feeding unnoticed on there. They have however been known by a variety of names, including wall louse, mahogany flat, crimson rambler, heavy dragoon, chinche and redcoat.

Fleas are insects (1/16 to 1/8-inch (1.5 to 3.3 mm) long), agile, usually dark colored (for example, the reddish-brown of the cat flea), wingless insects with tube-like mouth-parts adapted to feeding on the blood of their hosts. Their legs are long, the hind pair well adapted for jumping: a flea can jump vertically up to 7 inches (18 cm) and horizontally up to 13 inches (33 cm). This is around 200 times their own body length, making the flea one of the best jumpers of all known animals (relative to body size), second only to the froghopper. According to an article in Science News, "researchers with the University of Cambridge in England have shown that fleas take off from their tibiae and tarsi—the insect equivalent of feet—and not their trochantera, or knees. The researchers report their conclusion in the March 1 Journal of Experimental Biology." It has been known that fleas do not use muscle power but energy stored in a protein named resilin but the researchers used high-speed video technology and mathematical models to discover where the spring action actually happens. Their bodies are laterally compressed (human anatomical terms), permitting easy movement through the hairs or feathers on the host's body (or in the case of humans, under clothing). The flea body is hard, polished, and covered with many hairs and short spines directed backward, which also assist its movements on the host. The tough body is able to withstand great pressure, likely an adaptation to survive attempts to eliminate them by mashing or scratching. Even hard squeezing between the fingers is normally insufficient to kill a flea. It is possible to eliminate them by pressing individual fleas with adhesive tape or softened beeswax (or "cheese" wax) or by rolling a flea briskly between the fingers to disable it then crushing it between the fingernails. Fleas also can be drowned in water and may not survive direct contact with anti-flea pesticides.
Hooke's drawing of a flea in Micrographia
Fleas lay tiny white oval-shaped eggs better viewed through a loupe. The larva is small, pale, has bristles covering its worm-like body, lacks eyes, and has mouthparts adapted to chewing. The larvae feed on various organic matter, especially the feces of mature fleas. The adult flea's diet consists solely of fresh blood. In the pupal phase, the larva is enclosed in a silken, debris-covered cocoon.

Tick are small arachnids in the order Ixodida that, along with mites, constitute the subclass Acarina. Ticks are ectoparasites (external parasites), living by hematophagy on the blood of mammals, birds, and occasionally reptiles and amphibians. Ticks are vectors of a number of diseases, including Lyme disease, Q fever (rare; more commonly transmitted by infected excreta),[1] Colorado tick fever, tularemia, tick-borne relapsing fever, babesiosis, ehrlichiosis and tick-borne meningoencephalitis, as well as bovine anaplasmosis.

Yellowjacket is the common name in North America for predatory wasps of the genera Vespula and Dolichovespula. Members of these genera are known simply as "wasps" in other English-speaking countries. Most of these are black and yellow; some are black and white (such as the bald-faced hornet, Dolichovespula maculata), while others may have the abdomen background color red instead of black. They can be identified by their distinctive markings, small size (similar to a honey bee), their occurrence only in colonies, and a characteristic, rapid, side to side flight pattern prior to landing. All females are capable of stinging. Yellowjackets are important predators of pest insects.