“Spiders are insects”

It's a common misunderstanding that spiders belong to the insect class, largely because both are small, multi-legged creatures often found in similar environments, leading people to lump them together as "bugs" or "creepy crawlies". This casual use of terminology blurs the lines for many, making it easy to overlook the distinct biological differences. The lack of everyday necessity to understand arthropod taxonomy also contributes to the persistence of this myth, as the specific classifications aren't critical for daily life.

However, scientific classification clearly separates spiders from insects. Spiders are arachnids, a class that also includes scorpions, mites, and ticks. The most obvious distinction lies in their physical characteristics: spiders possess eight legs and two main body segments—a cephalothorax and an abdomen—and lack antennae. In contrast (Review), insects are characterized by six legs, three distinct body segments (head, thorax, and abdomen), and a pair of antennae. These fundamental differences highlight that despite their superficial similarities, spiders and insects are as distinct as birds and fish.

The misconception often stems from a general unfamiliarity with zoological classifications beyond broad categories. When encountering small, invertebrate creatures, it's simpler for many to default to the most common classification they know, which is often "insect." This tendency to generalize, combined with the visual similarities of having an exoskeleton and segmented bodies, reinforces the erroneous belief. Education on the specific anatomical features that define each group is key to busting this widely held myth and appreciating the diversity within the arthropod phylum.