Well neither mosquitoes nor gnats are considered 'bugs' through an entomological perspective – 'bugs' are insects in the order Hemiptera (have sucking mouthparts and semi-membraneous wings), while gnats and mosquitos are true flies in the order Diptera (one pair of wings and a pair of halters) and are of the primitive kind in the suborder Brachycera .

About the original question, mosquitos are selective about whom they suck blood from. Mosquitoes are equipped with excellent vision and the tools needed to sense humidity, carbon dioxide, heat, etc. Mosquitoes need vitamin B and cholesterol, and are attracted to the smells of lactic and uric acids. Other factors involved is excessive breathing, clothing colours, sweat, body size, etc. in determining if a mosquito wants to bite you .

Specific heart medications, blood pressure, high cholesterol, and cosmetics can attract mosquitoes .

Ask me any question you'd like on insects .