An estimated 2-3 million fatalities a year.

Can be found Worldwide; harmful in Africa, Asia and North America.

Using serrated mouth parts, female mosquitoes pierce the skin and inject saliva containing a thinning agent to liquidise the blood. Most people won't know that they have been bitten until the immune system reacts, resulting in red, itchy bumps that continue to itch for days after the initial bite.

Mosquito nets treated with DDT are the most effective way to keep them at bay, as well as combative sprays and treatments that can be applied directly to the skin. Wear light-coloured, long clothes in the evening. If travelling to malaria zones, ensure that you take your full course of tablets before, during and after your stay.

Mosquitoes are believed to have evolved around 170 million years ago during the Jurassic era (206–135 million years ago) with the earliest known fossils from the Cretaceous era (144–65 million years ago). They evolved in the land mass that is now South America, spreading initially to the northern continent Laurasia and re-entering the tropics from the north.  Ancestral mosquitoes were about three times the size of the extant species and they are a sister group to the Chaoboridae (biting midges).

Mosquitoes are principally nectar feeders with only the females requiring a meal of blood, except for the Toxorhynchites, which never drinks blood. This family includes the largest of the extant mosquitoes, the larvae of which are predatory on the larvae of other mosquitoes. These mosquito eaters have been used in the past as mosquito control agents with variable success. In the English language, the word Mosquito dates back to 1572. The word was adopted to replace the term "biting flies" to prevent confusion with the house fly. It is derived from the word fly and is related to the Italian moschetta and the French moustique.

The female mosquito sucks the blood of mammals, including humans. Mosquito bites often swell up hours after happening, causing a red ringed white bump about a centimeter in diameter. This bump can itch for days and over-scratching the bite can cause it to bleed. Continued over-scratching can cause scars. Mosquito bites can transmit diseases, such as Malaria, Dengue and West Nile Virus, so authorities in many areas take measures to reduce mosquito populations through pesticides or more organic means. An easy way to reduce mosquito populations in a residential area is the removal of standing water (where mosquitoes breed), and the use of repellents, such as DEET.

In much of the world, mosquitoes are a major public health problem; they are estimated to transmit disease to more than 69 million people annually. In the United States, Australia, New Zealand, the UK, Scandinavia, and other temperate countries, mosquito bites are mostly just a nuisance.[12]. Global warming is likely to increase or change the range of mosquitos in these countries, resulting in increased frequency of Dengue fever, Ross River Fever, Malaria and other mosquito borne diseases.

Worldwide, malaria is a leading cause of premature mortality, particularly in children under the age of five, with around 5.3 million deaths annually, according to Center for Disease Control. Most species of mosquito can carry the filariasis worm, a parasite that causes a disfiguring condition (often referred to as elephantiasis) characterized by a great swelling of several parts of the body; worldwide, around 40 million people are living with a filariasis disability. Most species of mosquito can carry the viral diseases yellow fever, dengue fever, epidemic polyarthritis, Rift Valley fever, Ross River Fever, and West Nile virus. Fortunately, mosquitoes do not transmit HIV. Viruses carried by arthropods such as mosquitoes or ticks are known collectively as arboviruses. West Nile virus was accidentally introduced into the United States in 1999 and by 2003 had spread to almost every state.