Fairies

The Pink Fairy, Green Fairy, and Blue Fairy are peaceful Critters found in the Surface layer or below which will attempt to lead the player to valuable treasures which include Crystal hearts, chest, life fruits, and Ore deposits. Fairies will only spawn if at least one Fallen Log has been left in the world without being destroyed, otherwise they will no longer spawn independently. The three Fairy variants all function identically.

There is a 1.392% chance that Fairy will emerge from a shaken tree in the Hallow at night. These fairies will spawn even if all Fallen Logs in the world have been broken.

While a fairy is nearby, enemy spawns are reduced, similar to (and stacking with) Sunflowers.

When a fairy spawns underground (or a captured fairy is 'consumed' while underground), they will fly to and follow the player for quite a while. If they are within range of a treasure, they will briefly circle the player, emitting a soft chiming noise, then head in the direction of the treasure. They keep a certain distance from the player in order to encourage being followed. Once the fairy reaches the loot it is leading the player to, it will circle it briefly, then disappear in a burst of glowing glitter which illuminates the area for a few seconds before dying out.

After 5 minutes, if the fairy has not led the player to a treasure and vanished, it will fly off.

On the Surface, Fairies can sometimes spawn near Fallen Logs, and can then be caught with a Bug Net. These fairies will not try to lead players to treasure; instead, when approached, they try to flee much like birds.

Fairies found underground, which lead players to the treasure, cannot be caught or hurt.

Treasure detected
Fairies may lead players to several different types of loot:
 * Chests (including already-opened Chests, empty Chests, and player-placed Chests).
 * Trapped Chests
 * Dead Man's Chests
 * Life Crystals
 * Life Fruit
 * Some Ores, in concentrations of at least 40 within a 7x7 square, specifically:
 * Gold
 * Platinum
 * Cobalt
 * Mythril
 * Adamantite
 * Palladium
 * Orichalcum
 * Titanium
 * Chlorophyte
 * Strange Plants

If there is no such loot in the vicinity, a Fairy will follow the player until it detects one, or until 5 minutes passes and the fairy just flies off.

Tips

 * Releasing a captured fairy will cause it to act like a fairy found underground; it will begin following the player and signal them once it detects treasure. Note that this means any released fairies cannot be captured again. This can be useful for locating chests anywhere in the world, especially if used in conjunction with a Metal Detector.
 * It may be useful to destroy any chests that are looted, as previously opened chests can be located by fairies, therefore wasting any fairy that happens to find the player.
 * Since Fallen Logs are the reason fairies spawn, it is unwise to destroy one.

Trivia

 * The tooltip for fairies and the name of its achievement, 'Hey! Listen!', is a quote from Navi, a Fairy character from.
 * The fairy encounter around the Fallen Log are nods to ; where 'Skull Kid' meets his fairies, Tatl & Tael, while he is taking shelter inside a Fallen Log.
 * These smaller fairies bear a strong resemblance to those summoned by the Fairy Bell, albeit much smaller in size.