Because the climate in Phoenix is exceptionally dry most of the year, problems with biting insects are not as common as they are in places that have more rainfall. Some of the biting insects in the Phoenix metropolitan area are nuisances, like biting ants and bed bugs. However, a few biting insects that live in the region can cause serious medical problems, especially from toxic spiders to disease-carrying mosquitoes.
Mosquitoes can be a problem in Phoenix when the weather warms in the spring until temperatures drop, typically in November. Stagnant water provides a breeding ground for mosquitoes, something which Phoenix has plenty of after a summer storm. Flood irrigation used in citrus orchards or cornfields in the metropolitan area also breed mosquitoes because the water can sit for days. The cities in Phoenix area may smog or spray for mosquitoes to control the insects during the summer to reduce the risk of West Nile virus. Exterminators include flying ants on their lists of bugs they kill when they treat commercial or residential properties. Flying ants have painful, harmless bites.
Ants are active all year long in the Phoenix area and the ants can bite. Ant bites are seldom serious, although the pain is immediate and intense. Since freezes in the winter are few, ants thrive all year long. The ants in Phoenix live in the soil, although they can invade homes where food is easy to reach, especially dry cat or dog food. Brown dog ticks inhibit grassy areas in Phoenix and often dogs pick them up from dog parks. The ticks can live in cracks in the home or near foundations if enough moisture is present, climbing on the dogs only to feed. Ticks can transmit tick fever to dogs but do not pose hazards to humans.
Although considered more of a nuisance than a major health hazard, bed bugs in the Phoenix area can be found in apartment complexes, hotels, motels and private homes. Bed bug eradication usually requires a professional exterminator. Spiders, although not technically bugs, can be toxic when they bite, especially the black widow spider. Tarantulas can bite but their bites are seldom serious. Both of these types of spiders are active at night.
Fleas are active all year, a problem in the Phoenix area because it seldom freezes and vegetation grows all year, providing a place for fleas to lurk, hopping on human or animal hosts. Once on a pet fleas can infest an entire home, requiring chemicals or natural treatments to kill both the fleas and the eggs in the home and on the pet. Fleas are the only jumping insects in Phoenix that bite.