Recently, I’ve taken a small break to establish a story bound universe, so that these questions can actually prove useful in the future
Recently, humanity has discovered a vast earth-like planet, with various ecosystems. However, in the desert, they find a creature that resembles one of Earth's many invertebrates, a scorpion.
The scorpion seems to act like ants, having workers, soldiers, and a queen.
The stinger on the queen's tail seems to resemble that of a flat leaf, with a bulbous lump in the middle. This is thought to be an evolutionary advantage for self protection. This is also because their desert-like environment is seen to have a little more foliage than Earth's deserts. When in danger the queen will not only sting its attacker, but will spray formic acid, mixed with a potent venom, which quickly kills said attacker.
The body of the queen has the texture of sharp rocks. This is thought to be a form of camouflage, but also a form of defense, in case she needs to move the colony to a safer location. In rare cases, she has been seen to have small plants growing on the back of her rocky-like body.
The head of the queen seems to possess two to four horn-like nubs. Four indicating health, and old age. The eyes are green and are described as slanted like compound eyes.
The pincers of the queen are fairly normal looking. They don’t have much of or any particular purpose other than to clamp down, hold, and tear prey.
The body of the soldiers look a lot more ridged and sharper than their queen or worker counterparts. Their pincers are a bit bigger than their body, and have hook-like nubs forming on the sides of said pincer. The stingers are a little bigger, and are capable of spraying formic acid further and in a wider arc than the queen can.
The body of the workers have a sleeker and smoother texture than the soldiers, but is still strong nonetheless. The pincers are smaller yet longer, and have a slight curve to them, indicating that they dig wide and long lasting tunnels. The head of the workers are flat in a way so as to block or wall-off the entrances of the colony from invading creatures. The stinger of the workers is small and doesn’t really spray all that much formic acid.
What evolutionary pressures would lead to such creatures, and are such creatures even feasible?
The scorpions are seen to frequently migrate. In a recently seen event it was found that sometimes many colonies will migrate together, but split off along the way to find suitable nesting locations. This also indicates that the scorpions are mildly passive to other colonies.