Final answer:
Fire's smoke serves as a natural insect repellant, providing protection for humans by reducing insect bites and the risks associated with them.
Step-by-step explanation:
An added advantage of the fire is that the smoke it produces helps to keep insects at bay. The relationship between fire usage and insect deterrence is a point of interest in biology, specifically in the study of survival and adaptation strategies of early humans. Controlled use of fire provided warmth, means of cooking, a way to shape tools, and, importantly, protection from insects. Smoke from the fire has compounds that many insects find repellant, discouraging them from coming close, thus reducing the likelihood of bites or stings for the humans gathered around the source of heat. This likely contributed to a more comfortable living and safer environment, particularly in areas where insects could transmit diseases or were simply a nuisance.