Pools of acid are only found inside the Worm. Acid is not as dangerous as lava, as it is possible to swim through pools of acid for a few seconds without taking any damage. However, the Spelunker will begin to take damage if they remain immersed in the acid for too long. Pools of acid also produce bubbles at their surface, similar to those blown by a Snail. Touching these will immediately deal one point of damage.