They also don't know what names are.
Wow. I don't know why, but I find that so sad. They are basically part of a colony, so they don't have a need for names. They have no "identity," so to speak because of that.
A good thing about Togashi is that if a character pops up in one of his series and isn't killed off, there's always a chance they'll pop up again at some point in the future.