Depending on the species, mosquitoes can grow to 4 to 6 mm long. Only the females bite and suck blood, which they need to produce the eggs. The males do not bite. Usually the mosquito larvae grow in stagnant (dirty) and shallow water. Moisture and heat speed up the developing cycle of the larvae.
Mosquitoes are mostly active between dusk and dawn and during the afternoon on warm humid days. When they are not active, mosquitoes usually hide in moist shady places such as hedges and woodland, or in houses. Mosquitoes are attracted to humans by CO2 (carbon dioxide), which they can detect from up to 6 metres away.
Long Haul travellers beware! Some of the most common diseases are transmitted by mosquitoes:
Malaria, West Nile virus, yellow fever, dengue fever, meningitis, threadworm and encephalitis are the most commonly cited examples of a disease spread by mosquitoes.
Often they are carried by tropical and sub-tropical mosquito species so make sure that you visit your GP bbefore you travel to exotic destinations to get some advice on what to take with you.