Ver Cuevana2. The Scorpions belong to the oldest land-based arachnides with over 1800 different species known to exist. Usually, they do not surpass the size of 10cm in length, but exceptions are know, such as the Emperor Scorpion (Pandinus imperator) which can grow up to become over 20cm in size. Scorpions are mostly active at night and hide away during the day. Take a look into the live of these amazing creatures!