Whiskers left on a horse serve which function?

• A. They are primarily for aesthetics.
• B. They are the horse's chief organ of touch.
• C. They help regulate body temperature.
• D. They deter insects.

Answer: (B)

Whiskers act as the horse’s main touch sensors. These special hairs, the vibrissae, are densely packed with nerves, so they pick up even light contact and changes in air flow around the muzzle and face. That tactile information helps the horse judge the size, shape, and distance of objects nearby, navigate in tight spaces or low light, and detect obstacles before they’re touched. Because of this, their primary role is to provide a highly sensitive sense of touch.

The other options don’t fit as well. They aren’t mainly for aesthetics, and whiskers don’t play a primary role in regulating body temperature or deterring insects. Keeping whiskers intact preserves this important sensory input for the horse.