Despite the prevailing opinion that mosquitoes drink blood, this is not true, because in fact mosquitoes drink blood. And they need it in order to conceive and breed. In general, female and male mosquitoes can drink water and nectar and live without blood feeding, but most species of blood-sucking mosquitoes are not capable of reproduction without blood feeding. Blood, unlike nectar, is a protein-rich food. The proteins contained in the plasma (liquid part of the blood) and erythrocytes are digested in the intestines of the "mosquito", and the resulting amino acids are used to synthesize the proteins of its eggs.
3-4 days after hatching from pupae, female mosquitoes mate with males. Fertilized females are looking for their victims. After drinking blood, females digest it for 2-3 days. During this time, eggs ripen in their ovaries, and then the female finds a suitable reservoir and lays eggs on the surface of the water. A certain percentage of females then die, and the survivors can drink blood again and only after that lay a new portion of eggs. (They do not need to mate again, since they have stored sperm reserves in the seminal receptacles - a special part of the reproductive system.)