Swarms are non-interactive groups of insects found to the west of Musa Point. They are harmless, and follow players around, although they cannot wander far. Multiple swarms can follow a single player at the same time.
Swarms were formerly a random event. They randomly appeared and attacked players, hitting one or two hitpoints (10 or 20 life points) of damage. The swarm would hit infrequently however and was not a threat to most players. Players could not attack the swarm, instead they needed to walk or run away from it to stop the swarm from attacking. Swarms would "steal" a player from combat if they were encountered in a non-multicombat area.
On release, the swarm was actually attackable, however it had an incredibly high Defence and only a few 1s and 2s (or 10s and 20s life points) were able to pierce through it. It also had an amazing amount of hit points and healed faster than normal. The ability to attack it was eventually removed, although something methods to deal damage to it remained. The ring of recoil worked against it for some time, however this ability was eventually removed. If a player had a familiar out in a multicombat area, it would attack the swarm, although it would only rarely be able to deal any damage.
It was considered one of the most annoying random events by many players since the only way to get rid of it, assuming they were unwilling to wait for their familiar to finish it off, was to flee the area and return.
- If a swarm occurred underwater, the examine text would be "A swarm of vicious plankton!" instead of the usual "A swarm of vicious insects!"
- The swarm is very similar to the sweetflies encountered during Trouble Brewing minigame.