Mosquito
Usually both male and female mosquitoes feed on nectar and plant juices. In many species the mouthparts of the females are adapted for piercing the skin of animal hosts and sucking their blood as ectoparasites. In many species, the female needs to get proteins from a blood meal before she can produce eggs. Hence, only female mosquitoes bites human to suck their blood. In many other species, she can produce more eggs after a blood meal.