The paired sensory appendages on an insect’s head used for smell and touch are its antennae.
Antennae, sometimes called feelers, are flexible structures covered with sensory hairs and microscopic receptors. Mechanoreceptors help detect contact, air movement, vibration, and pressure, while chemoreceptors detect odors and other chemical signals. These functions let insects explore surfaces, find food, recognize mates, and communicate through pheromones.
A typical insect antenna has three basic sections: the scape, attached to the head; the pedicel; and the flagellum, which is often made of many small units called flagellomeres. Their shapes vary enormously. Mosquito antennae, beetle clubs, butterfly knobs, and moth plumes are all specialized versions of the same basic appendage.
Antennae are not the only sensory structures insects possess. Eyes handle much of their visual input, mouthparts may detect taste, and some insects sense sound through specialized organs. The common wrong turn in this question is choosing palps: palps are also sensory, but they are mouthpart appendages rather than the paired head structures classically called antennae.