There are more than 1,700 species of Spiders in Spain, but all but a few are completely harmless.
The most dangerous of the spiders, to be found in Andalucia (Almeria in particular) and Valencia, is the Black Widow (Latrodectus tredecimguttatus). It’s sting is painful but not fatal.
The Funnel Web Spider (Macrothele calpeiana) is a nocturnal creature which inhabits damp, shady areas such as avocado groves. It is unlikely to be found in coastal areas.
The fearsome-looking Wolf Spider (Lycosa tarantula)) is to be found in the arid regions of Aragon. It does sting but it’s venom is quite weak.
The Mediterranean Recluse Spider (Loxosceles rufescens) can give a nasty nip although far less toxic than it’s African cousin.
The most common Scorpion in Spain is the Mediterranean scorpion (Buthus occitanus) and though not as dangerous as its North African cousin, it will still give you an extremely nasty sting. Wearing boots and thick socks is a good idea if you plan to hike in dry rocky areas. The European black scorpion is also present in Spain, preferring more northerly and wetter areas. It’s sting, fortunately, is short-lived. Scorpions have a penchant for resting in shoes, so be careful!