Spiders exist as different species.
Spider . They are the largest order of arachnids and rank seventh in total species diversity among all other orders of organisms . , at least 45,700 spider species , and 113 families have been recorded by taxonomists . Males of most species survive a few matings , limited mainly by their short life spans . Females of many species care for their young , for example by carrying them around or by sharing food with them . While the venom of a few species is dangerous to humans , scientists are now researching the use of spider venom in medicine and as non-polluting pesticides .