Why? It's almost dead, it can not pump out it's eggs anymore and even if it would: the ants would eat it too. This roach will not spawn itself any further, there's absolutely no danger anymore. What I find fascinating is that ants are some kind of garbage men. I didn't know that they have this kind of job, I always though that cats, mice or birds clean up roaches or other insects...
One big one being attacked by so many little ones : paralyzed,
"tortured", slow dying etc .. Not a sad sight in small view ! .. Yes.
such are their natural styles & ways