Trilobites ganged together to molt, just like modern day horseshoe crabs – themselves relicts of a bygone age. Such “social” behaviour is surprisingly old, as molting groups have been found dating back 520 million years, making me wonder why Arthropods never did develop intelligence as we know it in larger animals. Possibly it’s because they usually don’t reach huge sizes, though multi-metre long Eurypterids (“Sea Scorpions”) are known. On land they seem to be limited by their circulatory systems and the weakness of their chitin-based exoskeletons. Perhaps on a different world that might not be the liability it is here on Earth… imagine a low-gee moon with a dense atmosphere.
Maybe we will know one day.