Stronghold Threats
Beat a Silverfish
Silverfish are weak alone, 8 HP, 1 damage a hit, but they live inside the stone bricks of every stronghold and explode out in swarms the instant you mine the wrong block. The fight is about not feeding the chain.
Stop mining the moment one appears, funnel them into a 1-wide gap, sweep the cluster with Sweeping Edge, and keep a Splash Potion of Harming II to wipe a full nest in one throw.
SWARM ALERTCHAIN-SPAWN
14/ ~24 max
Don't mine blocks, each break wakes the chain
SWEEP -7
HARMING II -12
Sweeping Edge III, hit the clusterWhy the chain-spawn matters
Each infested block holds one hidden silverfish. When a silverfish is hit or a block is broken near it, the game pings every infested block within roughly a 21x21x11 box to release its silverfish too. In a brick-heavy stronghold room that cascades into a wall of two dozen bodies in seconds.
That is why the rule is don't mine more. The math flips once you accept you can't out-pick the spawns: clear what's already out with sweep attacks, throw one Harming II (12 instant damage, one-shots every 8-HP silverfish in the cloud), and walk away from the chiseled and cracked bricks. The portal room is the goal, not the loot you imagine is behind the walls.
Quick answers
+How much health does a silverfish have?
8 HP (4 hearts). A Netherite or Diamond Sword crit kills one instantly. Their threat is numbers, not toughness, they spawn in swarms from infested blocks.
+Why do so many spawn at once?
Breaking a block next to a live silverfish 'calls' all infested stone bricks nearby to release their hidden silverfish too. One careless mine can trigger 20+ in a chain reaction.
+What's the best weapon vs silverfish?
A sword with Sweeping Edge III. Silverfish cluster tightly, so a sweep attack hits the whole pack. For an instant wipe, a Splash Potion of Harming II does 12 damage to every silverfish in the splash.
+Where do silverfish appear?
Strongholds, they hide in stone bricks (regular, cracked, mossy, chiseled). They also spawn from infested blocks placed in mountain biomes, but the dangerous swarms are in stronghold rooms.
+Does Harming or Healing kill them?
Silverfish are not undead, so Harming hurts them (12 damage at level II) and Healing heals them. Use Harming, never Healing, against them.
+How do I avoid triggering the swarm?
Don't mine in a stronghold unless you must. If a silverfish is already out, kill it before breaking nearby blocks. Light the room and route around chiseled/cracked bricks instead of digging through them.