Scarab swarms are swarms of poisonous scarab beetles. Although their max hit is low, they are highly accurate with an extremely fast attack speed and are very likely to poison any players that they attack. They can crawl up from the ground randomly in some pyramid areas, and have a chance of spawning when the gold chest is opened in Pyramid Plunder.
They are only aggressive to players that cause them to spawn. Once the targeted player leaves, the scarab swarm will ignore other players and eventually despawn.
The scarab swarms that spawn in Jaldraocht Pyramid are simply known as Scarabs. While they have a lower combat level, they have the same appearance and behaviour.