Insects are fascinating creatures that exhibit a variety of characteristics that distinguish them from other animals. Among the features commonly associated with insects, the presence of two pairs of antennae is not one of them. Insects generally possess only one pair of antennae, which serve sensory functions such as touch and smell. This makes option A, the presence of 2 pairs of antennae, the correct answer to the question.
To elaborate, insects belong to the class Insecta and are quite diverse, with millions of species. Their anatomy typically includes three main body parts: the head, thorax, and abdomen. They have six legs and may have one or two pairs of wings. However, the misconception about having two pairs of antennae likely arises from confusion with other arthropods, such as crustaceans, which do have two pairs. This distinction is crucial in understanding the unique characteristics of insects.