Spiders are insects.
Spiders ( order Araneae ) are air-breathing arthropods that have eight legs and chelicerae with fangs that inject venom . Unlike insects , spiders do not have antennae . A herbivorous species , Bagheera kiplingi , was described in 2008 , but all other known species are predators , mostly preying on insects and on other spiders , although a few large species also take birds and lizards .