Visually strikingly similar to Headcrabs , these Swarm will rush to a corpse and burrow into it instead. The Swarm allow for multiple bodies to be infected simultaneously to cause a quick wave of Necromorphs that can overpower a person.quickly if not dealt with fast enough. The Swarm relies on dead human bodies to attack a person.they will burrow into the corpse and take it over. If the reanimated body is destroyed, the Swarm will rush over to the next available corpse and re-animate said body until killed. The Swarm will quickly insert themselves into a body if not stopped. Quickly dismember the body before the Swarm gets to it, or destroy them before they can reanimate a body for better breathing room.