If female mosquitoes are the only ones that bite humans and drink blood what do male mosquitoes eat?

Mosquitoes primarily feed on nectar from flowers. Both males and females will feed in this manner, sucking the nectar through a proboscis, much the same as a butterfly does. However, the female is also capable of drinking blood, an act called haematophagy. Females do not require blood to survive, but they need supplements, such as protein and iron, to enable them to develop and lay their eggs. Only the females drink blood because ( as said before) females need the supplements from our blood to lay their eggs. Also, the females are designed for drinking blood. So if you see a mosquito and it flies away from you , you will know it is a male.