does anyone recognise this story?

[steve @ home]

I wonder if anyone could tell me the title and author of this sci-fi story I read many years ago. here's what I remember of it..
A man bought some exotic alien pets about ant sized, kept them in a tank where he projected an image of his face. The 'ants' built little towns and split into different communities which then began fighting, much to their owner's amusement. Of course, they escaped eventually , grew enormously and turned on their former owner who got eaten.
I seem to remember a pun on the words 'maw' and 'ma'
does this jog any memories?

[Rabelais]

Sandkings by George R.R. Martin which was made into an outer limits episodes called The Sandkings, which differed slightly as the communal animals were samples from mars and not bought in a shop.

[steve @ home]

Thanks! I wonder if that episode is available on DVD. It would be interesting to see how my memories of the story were interpreted. Now I'm going to have to track down a copy! Amazon here I come...