Abyss ant

The abyss ant was an insect found mostly on multiple layers of the Abyss. They could occasionally be found on the Prime Material Plane when deliberately summoned by evil wizards and priests. Tanar'ri also sometimes got rid of a nest of abyss ants by gating the whole colony to the Prime Material Plane.

Combat
Abyss ants were immune to normal heat and cold and would take only half damage from magical heat or cold attacks. In battle, they would use either their stinger or their mandibles to attack. The stinger contained a powerful poison, which was almost purely acidic. The ants could also spit an acidic goo up to ten feet.

The ants had limited telepathy among themselves within 600 feet. If an ant was attacked, others in the colony were informed and would rush to its aid. The ants used this telepathy to call up reinforcements before launching an attack of their own. When engaged in combat, telepathy was used to coordinate the attack on a single target. If they successfully defeated their target, they would then attack the next enemy.

History
Though rare, colonies of abyss ants existed in some more temperate regions of The North.

Ecology
Abyss ants were known to act as servants of the Dark Seldarine goddess Lolth.