Brooding caverns

The Brooding Caverns are the network of caverns on Alternia which house the Mother Grub and her attendant Jadebloods, as well as the troll brood; eggs, wigglers, cocoons and young trolls, all in the first part of the troll life cycle. The laying Mother Grub, (or Grubs, although it is unknown if more than one Mother Grub is fertile at the same time), resides in a vast central cavern, receiving regular deliveries of genetic slurry carried in filial pails by imperial drones.

Young trolls emerging from their cocoons must face the Trials, a set of challenges designed to weed out the weak. Many trolls die both during this process, during their time as wrigglers, or due to deliberate culling. The brooding caverns are also where surviving young trolls are selected by their Lusii, and form their initial caretaker/charge bonds.

This location is mentioned frequently throughout Homestuck, although it was not visited in canon until the release of Hiveswap Friendship Simulator: Volume Three. Bronya Ursama is the head attendant Jadeblood to her section of the brooding caverns, seeing to the Mother Grub near the city of Thrashthrust. As such, her Friendsim route takes place within the caverns.