Spiders are from Araneae order. They are air-breathing arthropods that have eight legs and chelicerae with fangs able to inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all the order of organisms and are found worldwide on every continent except Antarctica. As of 2016, taxonomists recorded a total of 45700 species of spiders all over world. They  feed on common indoor pests, such as Roaches, Earwigs, Mosquitoes, Flies and Clothes Moths. If left alone, Spiders will consume most of the insects in your home. But too many of them might lead to too many spider webs all over the house making house dirty. They can be found around kitchens, Bedrooms, garages and living rooms. They stay in the walls above the ground. You can see them in the corners of the wall and in the ceilings.

Spiders are chelicerates and therefore arthropods. Spiders and scorpions are members of one chelicerate group, the arachnids. Scorpions' chelicerae have three sections and are used in feeding. Spiders' chelicerae have two sections and terminate in fangs that are generally venomous, and fold away behind the upper sections while not in use. In spiders, the cephalothorax and abdomen are joined by a small, cylindrical pedicel, which enables the abdomen to move independently when producing silk. Spiders produce spider webs which help them to catch their prey. The webs they produce are sticky and made up of silk fluid they produce form their body. Their eight legs help them to move in the web easily but other insects who gets trapped in the web can't get out of it with two legs.

Few spiders are considered good around houses as they reduce other pests. But if the numbers increase they can make walls dirty and difficult to clean.