Why Aren’t Spiders Considered Insects?

spider crawling on floor inside house

Now that it’s October, it’s time to decorate for Halloween! However, you may find that Mother Nature has sent some eight-legged, creepy-crawling interior decorators just in time to help out, adorning your porch and the dark corners of your home with their wispy, intricately woven webs.

You guessed it—today, we’re talking about spiders! More specifically, we want to address a common spider-related question: Why aren’t spiders insects?

Why Aren’t Spiders Insects?

Although they’re tiny invertebrates, just like insects, spiders—as well as mites, scorpions, and ticks—are not in the insecta class at all. Instead, they’re arachnids, a separate class of creatures. However, arachnids are classified in the same arthropod phylum as insects, which is a larger classification group. 

But what makes spiders and other arachnids different from insects to be classified as an entirely different class? It all comes down to distinctive physical characteristics and anatomy.

Arachnid vs. Insect Anatomy

As you probably already know, spiders have eight legs. This actually goes for all arachnids. Insects, on the other hand, have six legs. Notice that the number of legs for both classes (6 and 8) are even numbers. This is because the legs of both insects and arachnids are in pairs: Insects have 3 pairs of legs, arachnids have four. 

A more significant difference between arachnids and insects is the way their bodies are segmented or divided. Insects have three body segments, the head, thorax, and abdomen. Arachnids, however, are segmented into two main parts: the abdomen (just like insects), and the cephalothorax, which is a version of the head and thorax fused into one main body part. 

Some other differences between arachnids and insects include:

  • Exoskeleton: A hard suit of protective “armor” that only insects have. 
  • Wings: Arachnids (thankfully) do not have wings, like many species of insects do. 
  • Antennae: This is another insect-exclusive feature.

Whether You’re Dealing With Insects or Arachnids, We Can Help

Although insects and arachnids are fascinating creatures to study, you probably don’t want them hanging around your home uninvited! If you suspect an infestation of any pests inside the home, it’s time to call an expert to investigate the situation thoroughly, eradicate the presence of pests on your property, and implement long-lasting prevention.

Our team at Vulcan Termite & Pest Control has fulfilled that role for families in Alabama since 1965, and we would love to help you too! Call us at 205-663-4200 or contact us online today to learn more about our affordable, highly effective pest control solutions.