Infested is a harmful (negative) status effect in Minecraft Java Edition 1.21.
minecraft:infested
Give Infested II for 60 seconds (Java Edition 1.13+; duration in seconds, then amplifier where 0 = level I):
Remove the effect from the nearest player:
Infested causes silverfish to burst out when the affected entity dies, echoing the classic stronghold ambush inside trial chambers.
Silverfish attacks and related projectiles in trial chambers apply Infested briefly. No potion or item grants it; it belongs to the chamber infestation effect family.
Silverfish are weak but swarm, and an Infested death mid-melee can flood your footing. Kill affected mobs at range or on ground you control, and keep a sweeping weapon ready for the hatchlings.
The effect ID for Infested is minecraft:infested. Java Edition 1.13+ /effect commands use this namespaced form.
Run /effect give @p minecraft:infested 60 1 to get Infested II for 60 seconds. The first number is the duration in seconds; the second is the amplifier (0 = level I, 1 = level II). Remove it with /effect clear @p minecraft:infested.
Infested is a harmful (negative) status effect in Minecraft Java Edition, based on its registry category (harmful).
When the affected entity dies, silverfish spawn at its position. It is one of the trial chamber infestation effects and turns routine kills into ambushes if you are not watching for it.
Through silverfish attacks in trial chambers. The effect is short-lived and only triggers its silverfish spawn if the affected entity dies while it is active.