NBCSN Nationally Certified School Nurse Practice Exam 2025 - Free School Nurse Certification Practice Questions and Study Guide

Bed bugs primarily feed on human blood, which is essential for their survival and reproduction. These small, nocturnal pests have evolved to rely specifically on the blood of their hosts, with humans being the most common target due to their close association with inhabited spaces. The bugs use their specialized mouthparts to pierce the skin and extract blood, typically feeding when people are asleep, which allows them to go largely unnoticed.

While bed bugs are capable of feeding on the blood of animals, their preference for human blood is well-documented and is a significant reason they are often associated with human dwellings. The other options, such as plant sap, animal blood, and wood pulp, are not suitable food sources for bed bugs. They do not have the necessary mouthparts to extract sap or consume plant materials; hence, these options are not aligned with their feeding habits and biological needs. This specificity in their diet is why bed bugs are considered a common pest in settings where humans live and spend a lot of time.