Silverfish can spawn from silverfish blocks and monster spawners. They are also able to spawn, albeit rarely, underground in mountains biomes, inside of certain blocks. In the former case, they can only spawn in light level 11 or lower, except on top of stone blocks, where they can spawn at any light level. They also cannot spawn within a five-block distance of any player.
The blocks in which silverfish hide look identical to stone bricks, cobblestone, or regular stone, but take slightly more time to mine than normal with a pickaxe, and will take noticeably less time to mine without one. When the block is broken, Silverfish will pop out and attack. Destroying one of these blocks via creepers or TNT will kill the silverfish instantly before it has time to emerge. In regular gameplay, silverfish blocks occur rarely. If left alone, silverfish can re-enter some blocks, namely cobblestone, regular stone, and stone bricks.
When attacked, silverfish may awaken nearby silverfish within a 21x11x21 block area. This can lead to a terrifying swarm if there are enough in the vicinity, reflecting the similar behavior of Zombified Piglins and hostile wolves. An uncontrolled swarm can quickly destroy dozens of stone bricks within a Stronghold. They scurry away after a player moves a short distance.
Silverfish can cause damage to a player. This occurs when a silverfish is touching a player and a change of the Y-coordinate (elevation) of either a player or silverfish occurs. This can easily kill a player, since - in a confined space - receiving damage causes a player to perform a short "hop," which counts as a Y-cord change. This allows the silverfish to damage a player again as a player is coming back down from the initial "damage hop". Formerly, silverfish could not damage a player directly but would scurry towards a player and push them around, with the tendency to be aggravating and potentially dangerous (e.g. when around lava/fire). If a silverfish is standing on soul sand, it will slowly take suffocation damage and die.
It is advised to avoid conflicts with silverfish altogether, as they will simply generate a massive swarm that can easily overwhelm an inexperienced, unequipped or unprepared player. If a player does, however, choose to challenge silverfish, it is advised that they wear armor, as silverfish can quickly deal massive amounts of damage as the swarm grows. Melee weapons are advised, as silverfish are the smallest mob that naturally spawns. If a player is experienced with a bow, then using ranged combat may reduce the size of a swarm. If you are a skilled enough player to have armour enchanted with high levels of thorns, this can be very effective, as the silverfish will kill themselves when they attack you.
A simple tactic to combat a swarm of silverfish is to simply build a two-block high pillar and attack from there, as silverfish do not have any range and only deal damage via contact. The use of splash potions is not recommended as nearby silverfish will be provoked, causing greater difficulty with combating silverfish.
A sword with high level enchantments can also be very efficient, e.g. a diamond sword with Sweeping Edge and a high level of Bane of Arthropods can take out an entire swarm of silverfish in one swipe.
- The I.D. for the silverfish block is 97 and can be hacked in through mods or by using the
/givecommand in multiplayer, levels with cheats activated, or through LAN.
- Silverfish, along with endermen, had a placeholder sound in Beta 1.8 but they got their own sounds in the 1.0 Update. Before 1.0, silverfish shared the same sound with spiders.
- Silverfish blocks in Creative mode can be found under "decoration blocks".
- If a silverfish block is destroyed in Creative mode, a silverfish will not spawn.
- This also happens if the difficulty is set to peaceful and a player breaks a silverfish block because the silverfish is a hostile mob.