An ant farm is designed to replicate much of the natural environment that ants normally occupy. But there are numerous differences between being sandwiched between a couple of sheets of plastic and living in a natural underground nest.
What Sort of Ants?
The ants that you’ll probably have in your farm will almost certainly be Western Harvesters, Pogonomyrmex occidentalis. This species is found over much of continental North America although it tends to prefer drier (or, in bio-speak, xeric) areas. It therefore predominates in the western parts of the continent.
They are normally found in nests of 8000-12000 individuals. These are divided up into various castes; workers (about 90%), soldiers (about 8%) with the remainder being drones and, of course the queen. In an ant farm you’ll probably have about 25 workers. Now, it’s not clear what effect the absences of a queen has on the workers. We do know that the activities of the worker ants are mediated through the effect of hormones released by the queen. There’s no observable difference in behavior when the worker ants have no queen to minister to, and no hormones to respond to, but of course we have no idea what they are thinking.
Which brings us to the next question – do worker ants think at all? All the available evidence suggests that these creatures have about one hundred neurons in their nervous systems. With a complement of 100 brain cells, it seems that most of ant behavior is ‘hard-wired’ that is, any behavior we observe is the response to external stimuli, rather than the result of any conscious thinking behavior (or ratiocination). So it’s very likely that your inmates will be unaware of any difference between a natural nest and the ant farm in which they find themselves. The very fact that your Western Harvesters create and maintain their tunnels just as they would in nature should give you confidence that your ants are happy and content.
How long will your ants live? Now, as you’ll appreciate, it’s not at all easy to track an individual worker ant in the wild over the period of its natural life and any estimates of natural worker ant life-length need to be taken with caution. But it’s thought that average life-length is about 100 days. But that is in the absence of predation. In the wild very few worker ants will live that long. It’s a tough place out there, and every ant has to struggle for its life against birds and other predators every day. Your ants, in their cozy ant farm, may well live out their lives in peace and tranquility so, as far as we can say, you have no need to fear for their comfort. It’s not natural but natural isn’t always best when natural means a daily battle for survival.