Sandkings

When Simon Kress returned to his home planet of Baldur from an offworld business trip, he was amused to find that his tank of Earth piranhas had cannibalized themselves into extinction, and of the two exotic animals that roamed his estate, only one remained. Now, in search of some new pets to satisfy his cruel pursuit of amusement, Simon finds a new shop in the city where he is intrigued by a new lifeform he has never heard of before ... a collection of multi-colored sandkings. The curator explains that the insect-like animals, no larger than Simon's fingernails, are not insects, but animals with a highly-evolved hive intelligence capable of staging wars between the different colors, and even religion--in the form of worship of their owner. The curator's warning to Simon about the regularity of their feeding, unfortunately, was not taken seriously.... ["Outer Limits" Episode]