Shabina Akhtar explains: Mosquitoes are often seen forming swarms above our heads or some high surface. This is because the swarms are the place where mosquitoes of opposite sexes meet and then move on to a secluded place to mate. Generally they prefer dark secluded areas for their interlude.

Dr Hiranmoy Mukherjee, head of department at the Medical Entomology Centre says, “The male and female mosquitoes before mating make a nuptial dense (swarm) above any high surface.” The male mosquitoes generally form these denses and wait for suitable females. When a female enters the swarm, the males immediately pick up her flight tone (the buzzing sound), which is different from theirs. Coupled with one, she flies to some protected place to mate. After their interlude, the female goes for oviposition (laying eggs), while the male returns to the swarm, on the outside chance that he’ll get lucky once more.

Perspiration, warmth, body odour, carbon dioxide, and light attract mosquitoes. Perspiration generally contains some amount of cholesterol and vitamin B complex, which the mosquitoes need but cant manufacture. They can, however, detect which host is the richest source of these ingredients and bite accordingly. The plentiful presence of these substances on some people makes them more attractive to mosquitoes than the others.

The question was sent by Ayan Nath from Jadavpur, Cal-32