Which insect does NOT feed on blood?

The book louse is the correct answer because it is a member of the order Psocoptera and primarily feeds on mold, detritus, and organic matter found on surfaces such as books, paper, and other materials. Unlike fleas, bed bugs, and mosquitoes, which are all known for their blood-feeding habits, book lice do not have the physiological adaptations or behaviors necessary for blood consumption. This distinction is important when studying insect interactions with humans and their environments, particularly in the context of public health, as blood-feeding insects can play significant roles in disease transmission.