Pillbox joke anyone?

The last time I descended the 80 broken steps down from the corner of Newhaven Fort’s parade ground into the bowels of the earth, they were unlit, but for our torches, and the ruins of the broken tunnels echoed to our excited teenage voices. The fort was just a playground for us then. Dangerous, with its broken concrete, twisted metal and dark subterranean caverns, but still a place where we explored and played.
That was during the two decades of decay between when it was decommissioned in the early 1960s and when it was reconstructed as a heritage tourist attraction in the early 1980s.
When I recently took the 9-year-old for a look around, much had changed, but I still recognized some of the passageways and corridors, now lit by fluorescent tubes, and the long stairs down to the caponier were still dank and musty from disuse.
It’s always good to learn a bit of new jargon; a caponier is an earth-covered fortified construction jutting out into a defensive ditch allowing the soldiers to fire through small slot windows to defend the ramparts from assault. It’s a kind of semi-subterranean pillbox tacked onto the lower region of the fort.
And what better creature to find down there than hundreds of pill woodlice, Armadillidium vulgare? Gathered into huddles in the darkness, they were crying out for a pill- or pillbox-based collective noun. A tablet? A dose? A caponier, perhaps?