Difference Between Insects and Spiders

Insects vs Spiders

The maximum number of species in the Animal kingdom belongs to the Phylum: Arthropoda, where both insects and spiders belong. Insects and spiders are considerably different with many features. The body forms (e.g. Legs, distribution of the body parts, eyes…etc) and most interestingly, the number of extant species differ vastly between insects and spiders. Insects inhabit almost all the habitats and the spiders are a little selective in choosing a home. Naturally spiders mostly are enemies of the insects.


Belonging in the Class: Insecta, they have three tagma (specialized segments of the body) called; head, thorax, and abdomen. There are three pairs of legs originating from the thorax. The head has two compound eyes and two antennae for sensory functions. In the abdomen, anus opens the oviduct and rectum to the exterior. Insects can sustain in almost all the ecosystems due to their extreme adaptability, and present day there are more than 1,000,000 described species. It is expected to that there are 6 – 10 million extant species of insects on the Earth. This extremely higher number of insect species in the world lifts their importance. Some of the very common insects are butterflies, ants, bees, weevils, paddy bugs, crickets, grasshoppers, leaf insects, mosquitoes…etc.


Spiders are interesting creatures in the Animal kingdom with about 40,000 recorded species. The body of the spider is segmented into two tagma; cephalothorax (fused head and thorax) and abdomen. Abdomen is mainly the reproductive unit as in the other insects and arthropods. The cephalothorax bears four pairs of legs for locomotion and weaving webs. The spiders have four pairs of compound eyes and no antennae. Their eyesight is sharper and which is very useful in capturing the prey items baffle in their webs. The females make silk egg cases, for the eggs to be kept until the small spiderlings come out of them. At a time, a female lays several hundred of eggs into the woven silk egg case.

Insects vs Spiders

- These two distinct groups of arthropods are mostly smaller in size, and they both have a chitinous cuticle. This cuticle serves protection and gives a definite shape for the body.

- Most of the insects are social while the spiders are not in many instances. Some social spiders are recorded by the scientists.

- The food habits of insects and spiders unveil another difference between the two. The spiders are always predators whereas, some of the insects are predators , some are parasites (both internally and externally), and some are plant zap feeders.

- The number of eyes and legs are more in spiders. But, the spiders do not have antennae, providing a major difference from the insects.

- The abundance and the adaptability are immense in insects than any of the animal groups. Therefore, that makes them the most successful animal group in the world in terms of the number of species.

They being useful for many activities of humans, the interest of people has been attracted towards both these animals. The medicinal values, medical values, economical values, aesthetic values, and research values are only a very few of the appeals of both spiders and insects.