Does, say, a worker ant ever go rogue and try to eat the Queen, or anything like that? More generally, are eusocial animals always thoroughly adherent to their biologically prescribed roles?
Yes, ants cheat, but it’s mainly about reproduction.
How Cheating Ants Give Themselves Away
Even ant royalty is corrupt:
Fascinating!
From the second article:
Is this speculation, or has such enforcement of genetic equality actually been observed in ants?
I’ve read somewhere that this can happen under the influence of the chemical substances exuded by some beetles, which thus benefit by imposing as the queen.
I guess the poor ants might plead temporary insanity…
Yes, some beetles move into an ant colony, and rub ant all over themselves, and since they smell like an ant the other ants think they’re an ant. So they go around eating larvae and stuff and ants can’t figure it out.
Not strictly ant-on-ant crime though.
You probably know about Ant Slavery, right? Slave-making ant - Wikipedia
Again, probably not exactly what you were looking for, since it’s one species of ant enslaving ants from another species, not a worker ant going rogue against their own colony and getting tattoos and stuff.
There are also multiple species of ants which have no workers, but whose queens sneak into established ant hives of other species that do have workers. They ambush and murder the resident queen, and then smear her bodily fluids over themselves to fool the resident workers into thinking that they are the queen. The resident workers then raise the parasite queen’s eggs, all of which hatch into new drones and queens to infect more nests.
This is one of the most interesting threads I have seen in a long time!
Are there any animals that have anything approaching an organized criminal justice system (e.g. with designated justice officials, investigations, trials, imposition of specific sentences, probation, etc.), or is it more a case of the “behaving” animals taking justice into their own hands and dispatching the offender rapidly? E.g. do ant colonies sometimes have ants that receive extra special supervision due to a prior offense committed by the ant?
I don’t think ants have enough brain cells in their little heads to do much more than simply follow chemical cues, which has through evolution led to some awkward situations such as slavery, usurper queens and beetles chemically dressed up as ants.
Dereliction of duty does happen in a sense. Just look at a group of ants sucking at a drop op syrup like it’s a crack pipe - if they find food they’re supposed to take it home for the greater good, but some stuff is apaparently just too good to share. I’m afraid they’re never courtmashalled for their behaviour though.
On a side note: an interesting novel in this respect is Les Fourmis (The Ants) by Bernard Werber. The story uses actual ant behaviour and colony mechanisms to tell the story. It was long ago that I read it, but if I’m not mistaken the story revolves around some in-colony conspiracy. Dunno if it was ever translated into English. It should be.
Well, kangaroos are known to hold court, though their justice system seems a bit rigged.
This whole thing about ant queens invading a worker colony is giving me ideas about squishing a queen ant, keeping her scent on my finger, and proceeding to rule an ant colony of my very own! Do my bidding, lowly ants! Bring me my beer! …and find the remote while your at it…
Won’t anyone think of the larvae!
Fascinating thread! Didn’t know ants could be so sneaky, selfish and subversive.
Nitpick: It’s “court-martialed.”
Oh yeah? How do you know what ants call it? 
They probably call it something like: two squirts of dihydro-methanol followed by one squirt of pheno-carbolic acid.
Believe it or not, I got through all my schooling without ever taking a chemistry class!
My Aunt Annie told me.
Do you want ants? Cuz that’s how we get ants.
Or, Malorys.
Supposedly, there are “crow trials” (they would gather to punish/kill an offender)but I wouldn’t know if they have any basis in reality.
Chimps seem to be sensitive to fairness.
I recall reading somewhere that for ants, things are either Done or Not Done.
I want to know more.
I feel a positive thrill just imagining such things, but I’m afraid that the large majority of - if not all - animals simply lack the brain capacity to even begin to grab the moral concept of right and wrong which leaves ‘crime’ as a concept far beyond their grasp, let alone trials and justice. Even in human history that whole idea is a relatively modern concept. For a long time we didn’t even get much further than some debate whether an offender should be killed or ‘only’ ostracized from the community
As for my misspelling of court martialed: I’m not a native speaker of English and always embarrased when it shows