[dredmorbius]

The grasshoppers self-activate as locusts under crowded conditions. Once they enter the swarming phase, the behaviour is self-perpetuating, generally until foid supplies are exhausted. With high mobility, this can take time and strip tremendous areas of land.

By stocking a sufficient population early on, in sufficient confinement,, it might be possible to create a perpetuating, expanding, swarm.