The Blodex resemble black ants, with exo-skeletons instead of skin and large eyes, though they have eight limbs as opposed to six. Each hand has two fingers and a thumb, while their feet are three-toed.
The Blodex found Sonic the Hedgehog after he was teleported to their planet due to fighting the Xorda on Mobius. Through the use of their antennae, the Blodex have an extrasensory ability eerily similar to Mobian Fire Ants which allowed them to access Sonic's memories and learn his language and then project back into his mind in his own tongue. A rather hospitable people, the Blodex allowed Sonic to stay in their capital city while arranging off-planet transportation to get him home the next day. While exploring the city with his Blodex guide, Deeble, Sonic found himself facing the Statue of Aypex, an ancient hero of the Blodex who saved them long ago. What Sonic found strangest was that in each of the statue's six arms was a Chaos Emerald that was colored red and began to wonder if there was some connection to his planet's own emeralds. Later that same evening, the Bzzzz, another insectoid race with whom the Blodex were mortal enemies, attacked the city with their Queen. In response, Sonic ran to the Statue of Apyx to use the emeralds and hopefully gain the form of Super Sonic. However, Super Sonic appeared as a separate entity, destroyed the Bzzzz and then began attacking the Blodex. The evil manifestation caused great devastation on their home planet, which would have turned out even worse had Sonic not intervened.