Silverfish nests

These nests would spawn deep underground, consisting almost entirely out of the blocks silverfish can spawn from. there would also be Spawners inside of the nest, 1-2 depending on the size of the nest. The nest would be completely closed off, and the only way in would be to mine into it. Silverfish would defend the nest from any intruders at all costs, relentlessly attacking any entering players, Silverfish would spawn from the blocks there as well as from the spawners. There would be 1-2 chests inside, often containing dungeon loot inside.

As a bonus, perhaps silverfish could also have a new drop, such as silverfish scales, which could be used for crafting chainmail armor or iron nuggets, making it better to keep the spawners for farming purposes.