Are there volcanoes on comets?

Volcanoes may not just exist on moons and planets. A comet orbiting between Saturn and Jupiter seems to have its own signs of icy volcanism, spewing frozen material instead of hot lava. Rather than a single stagnant mound, however, the eruptions come from a single location multiple times before eventually traveling to another point in the icy crust.

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What is the definition of a volcano?

Haven’t read article yet.

But what we know from Rosetta at 67P is that rather than volcanos, comets ha e what are called “active pits”. These are the relatively small areas of the comet surface that spew out plumes of matter into the void.

Active pits are hollows that are almost semicircular in shape and, afaik, are lighter in colour than the surrounding dark material.

As the comet rotates, different active pits spring into action.