Ask a Naturalist: Are spiders insects?
February 09, 2021
Written by Kristen Angelini
No. Spiders are not insects. While spiders and insects are distant ancestors, they are not the same type of animal.
Both insects and spider are invertebrates with an exoskeleton, though there are a handful of characteristics that set insects apart from spider. Insects fall under the class Insecta while spiders fall under the Arachnida class. An insect has six legs, two compound eyes, three body parts (head, thorax, and segmented abdomen), two antennae, and generally four wings.
Comparing the body of an insect to that of a spider, you will notice quite a few differences. Spiders, and other species in the Arachnida group, have eight legs with only two body parts as well as eight eyes. A spider’s head and thorax are fused while their abdomen is not segmented. Spiders also do not have distinct wings or antennae like insects.
Arachnids belong to an even bigger group called Arthopods, which also include insects and crustaceans. This is the largest group – 80% of animals – in the animal kingdom.
Get a little messy with paint and create your own handprint spider! Click here or the image below to learn how!
Compare the two photos above to discover the physical differences between an insect and a spider. Then, explore your backyard, neighborhood or local park and see if you can find an insect or a spider! If you have one, use a magnifying glass to really get up close and personal to this animal. Is this critter an insect or a spider? What evidence do you notice that helps you conclude your decision?
Click here to learn more about the differences between spiders and insects on University of California Agriculture and Natural Resources's (UCANR) blog.