What underground, for example burrowing or tunnelling creatures on earth, have underground organisation/societies, that are intricate enough for interesting narrative features, for example friendships or self expression?
Worms for example have no society at all, and are no good.
They may be unfamiliar, or even without analogies, to human culture.
Well you could use these:
Meerkats are small burrowing animals, living in large underground networks with multiple entrances which they leave only during the day. They are very social, living in colonies averaging 20–30 members. Animals in the same group regularly groom each other to strengthen social bonds.
Meerkats demonstrate altruistic behavior within their colonies; one or more meerkats stand sentry, while others are foraging or playing, to warn them of approaching dangers.
Meerkats also babysit the young in the group
Meerkats are also known to share their burrow with the Yellow Mongoose and ground squirrel, species with which they do not compete for resources.
These creatures even had their own show, based on their society and personality. So they would be possibly be a good fit. The squirrels and Mongoose don't really live alone in networking burrows.
The tunnel systems built by naked mole-rats can stretch up to three to five kilometres (2–3 mi) in cumulative length.
The naked mole-rat is the first mammal discovered to exhibit eusociality. This eusocial structure is similar to that found in ants, termites, and some bees and wasp
By evidence of their workers these creatures have a pretty social atmosphere and caste system.
Some species (such as Tetramorium caespitum) attack and take over neighbouring ant colonies. Others are less expansionist, but just as aggressive; they invade colonies to steal eggs or larvae, which they either eat or raise as workers or slaves.
Not all ants have the same kind of societies. The Australian bulldog ants are among the biggest and most basal of ants. Like virtually all ants, they are eusocial, but their social behaviour is poorly developed compared to other species.
So a story featuring the different types of ants would be interesting.
Worker termites undertake the labors of foraging, food storage, brood and nest maintenance, and some defense duties in certain species.
The soldier caste has anatomical and behavioural specializations, providing strength and armour which are primarily useful against ant attack. The proportion of soldiers within a colony varies both within and among species.
Highly social, prairie dogs live in large colonies or "towns" – collections of prairie dog families that can span hundreds of acres. The prairie dog family groups are the most basic units of its society.7 Members of a family group inhabit the same territory
A prairie dog town may contain 15–26 family groups.7 There may also be subgroups within a town, called "wards", which are separated by a physical barrier. Family groups exist within these wards. Most prairie dog family groups are made up of one adult breeding male, two to three adult females and one to two male offspring and one to two female offspring.
Burrowing owls can be found in grasslands, rangelands, agricultural areas, deserts, or any other open dry area with low vegetation.2 They nest and roost in burrows, such as those excavated by prairie dogs (Cynomys spp.).
Not really answers, but still notable:
Here's a few I can think of
I linked Naked Mole Rats because they're probably the most interesting (and crazy!) They're like the ants of mammals. They have a "queen" who is the only female allowed to breed. They have weird adaptations allowing them to dig while breathing underground. They're resistant to cancer. They have social classes. Prarie dogs and Meerkats are similar but spend more time aboveground. Some Ant and Termite colonies have very intricate social structures. Some even have "prisons" and "farms!"
