Endermite

Endermites are the smallest hostile mobs in Minecraft.

Spawning
They have a 5% chance to spawn when throwing ender pearls, and can be spawned with spawn eggs.

Drops
Endermites drop 3 experience when killed by a player or tamed wolf.

Behavior
Endermites will attack players within 16 blocks of them.

Endermites despawn within 2 minutes, regardless of the player's distance from the endermite, except for when they have been named with a name tag. If a mob attacks an endermite, any endermites in the area will become hostile towards that mob.

Endermites can attack endermen when spawned with a spawn egg.

Endermites, being arthropods, are weak against weapons with the Bane of Arthropods enchantment.

Endermites will take suffocation damage if standing on soul sand, because their height is less than that of a slab.

Endermites will spawn two portal particles around them.

They will attack iron golems.

The endermite is based on the silverfish, so they will sometimes try to enter blocks when idle, but can't.

Endermen
Endermen will attempt to kill endermites if they were spawned from ender pearls.

Data values
Endermites have entity data associated with them that contain various properties of the mob.