Spiders, like scorpions, pseudoscorpions and mites, are part of the Arachnida class. There are around 40,000 species of spiders in the world, including 700 in Quebec. Specialists estimate that there are many other species that have yet to be discovered.
Spiders’ life cycles vary by species. These arthropods do not undergo metamorphosis. Young spiders, called spiderlings, are simply a smaller version of the adult. Like insects, growing spiders shed their “skin” during moulting. The exoskeleton peels off the spider’s back, and the spider uses its legs to pull it off. The number of moults varies according to species.
Spiders are voracious predators and consume large quantities of insects. By feeding on insects, they keep populations from getting too large, providing a form of biological control in many different natural and agricultural environments. By extension, they play an important role in pest control.
Spiders are present everywhere in nature. However, many species live inside houses and buildings. Spiders that live near humans, using their gardens as habitats or nesting areas, are called synanthropes.