Intelligent Swarm

Intelligent Swarm (知性を持った群体) are creatures that inhabit both YGGDRASIL and the New World.

Appearance
Just as the name suggests, it is most likely a mass number of small insect monsters coming together to form a swarm.

Abilities
Intelligent Swarms seem to have the capacity to carry out some form of surveillance.

Trivia

 * In the Web Novel, it was mainly the Intelligent Swarm who are given the duty of observing the surroundings of the Great Tomb of Nazarick,with the occasional help from Kyouhukou every now and then.