In 2370, the USS Enterprise became infested with these organisms, which arrived on board along with a new warp plasma conduit which had been recently installed. The organisms had originally been attracted to the conduit on planet Thanatos VII, where the conduit had been manufactured using a new interphasic fusion process. The organisms then lay dormant in the conduit until the Enterprise crew activated the warp core.
These organisms fed on the crew's cellular peptides, a process which would eventually have led to their deaths. Fortunately, Lieutenant Commander Data's positronic subprocessor detected a high-frequency interphasic signature from the organisms, leading to their discovery by the crew. This detection manifested itself as unusual imagery within Data's dreams. Stabbing the organisms with a knife did not affect the creature, as evidenced by Data's attempt against Deanna Troi.