Critters

Critters are harmless entities that don't interact with the player in any way, except in that they can be killed by both players and enemies. All critters have 5 health and serve as ambient entities. Most critters can be summoned by means of a statue, but will otherwise spawn randomly in any environment that supports them.
All critters can be caught with a Bug Net, except for and . Additionally, critters from The Underworld can only be caught with a or . When caught, the critter can be carried around the player's inventory (or placed in storage), and can be released again by being used like any other item. On , critters spawned from statues cannot be caught; attempting to do so will cause the critter to disappear in a puff of smoke.
Most caught critters can be used as fishing bait and crafted into food. All caught critters can be caged to create animated display furniture. Once crafted, the critter cannot be released. Most critters are caged in Terrariums, however Butterflies, Dragonflies, Fireflies and Lightning Bugs are caged in Bottles, and both Goldfish and Pupfish are caged in Bottled Water. Bottled Fireflies and Lightning Bugs also function as valid light sources.
On , some critter types have a rare golden variation that has a / chance of spawning instead of a normal one and can be detected by the Lifeform Analyzer. Visual identification is helped by the sparkles they emit when alive in the world.
There are currently 91 / 41 / 28 / 8 different critters.
== Types ==
Critter	Critter	Environment	AI Type	Rarity	Sell	Bait Power	Notes
=== Butterflies ===
Butterfly	Butterfly	Environment	AI Type	Rarity	Sell	Bait Power	Notes
=== Dragonflies ===
Dragonfly	Dragonfly	Environment	AI Type	Rarity	Sell	Power	Notes
=== Gold critters ===
Critter	Critter	Environment	AI Type	Rarity	Sell	Bait Power	Notes
== Boss summon critters ==
Critter	Critter	Environment	AI Type	Rarity	Sell	Power	Notes
== Gallery ==
File:Placed Birds.gif
File:Placed Squirrels.gif
File:Placed Bunnies.gif
File:Placed Ducks.gif
File:Placed Scorpions.gif
File:Placed Butterflies.gif
File:Placed Penguin.gif
File:Placed Worms.gif
File:Placed Grasshoppers.gif
File:Placed Jungle Bugs.gif
File:Placed Snails.gif
File:Placed Frogs.gif
File:Placed Mice.gif
File:Fish Bowl (placed).gif
File:Placed Fireflies.gif
== Notes ==
* Most critters will spawn in the place of enemies near NPCs. Mice, however, will generally not spawn near NPCs.
* The spawn rates and spawn caps of critters are affected by many of the same factors as those of hostile enemies, so Water Candles, , Battle Potions, adjusting the Enemy Spawn Rate slider in , Calming Potions and Sunflowers will affect critter spawns.
* Critters caught with a Bug Net when the player has a full inventory will be dropped in the world as items rather than released.
* Critters regenerate health, this can be seen by hitting them with a low damage weapon/tool, like a Copper Axe, Copper Pickaxe or a Wooden Hammer.
* Trying to release a Goldfish will cause the goldfish to be consumed.
* Once a critter is put inside a cage, bottle, or jar, that single critter can no longer be released, and will stay in there forever. An alternative is to simply release the critter into an enclosed area, though the critter can then despawn if a player travels too far away.
* Attempting to catch an Underworld critter with an ordinary Bug Net will result in the player being set On Fire! for 5 seconds and the critter will not be picked up.
* Many critters which appear to be two or even one blocks tall in fact require a full three blocks height to move. If manually placed in a two-block high space they will be unable to move. 
** Three-block-high critters only includes Penguins 
** In contrast, Worms, Snails, Mice, Sluggy, Grubby and Buggy can crawl in one-block high spaces.
** Butterflies can fly in one-block-high spaces.
** Grasshoppers, if placed in a small space, can jump downward through the blocks beneath them until they reach open space.
** Birds in a one-high space can fly upwards through at least the block above them.
== Tips ==
* With several NPCs acquired, keeping Water Candles around your suitable housing will cause more critters to spawn, without spawning enemies.
* To find exactly how much damage an enemy does, a critter can be placed on the enemy. Critters have 0 defense and enemy damage to it will not vary unlike most situations of dealing damage. Projectiles from enemies will do varying and reduced damage to critters, so it will not work for measuring projectile damage.
* Early game, before a player can craft enough torches to place around a base, a player can use critters to alert them when an enemy is approaching.
* For eligible critter types, 1/400 / 1/150 spawns get a valuable golden critter. But since all critters are subject to a spawn cap, few new ones will spawn unless you are industrious about collecting all those "worthless" critters, increasing turnover.
* During a Blood Moon, Bunnies, Goldfish, and Penguins will transform into hostile enemies: Corrupt Bunnies, Corrupt Goldfish and Corrupt Penguins in a Corruption world ( and Vicious Bunnies, Vicious Goldfish and Vicious Penguins in a Crimson world). So it is recommended for players who are ill-equipped or have low health to either kill or capture any bunny, goldfish, or penguin in their vicinity before nightfall happens. Critters that have been placed in inventory, storage, or cages will not be affected. These same critters can be transformed manually into their corruption form by throwing Vile Powder at them, and their crimson form by throwing . All Bunnies, Goldfish, and Penguins spawned from statues will transform into enemies if they are spawned during a Blood Moon. Once these critters have transformed into hostile enemies, they can no longer be caught with a Bug Net.
* Having a in the inventory will prevent the player from dealing damage to all critters, except for the Explosive Bunny. This includes traps placed by the player.
*Lava critters like Hell Butterfly, Lavafly or Magma Snail may be useful for players wanting to fish in the lava with any poles (on version 1.4.0.1 or higher), but can be pretty hard to find. Critters spawn faster when the player don't move so much, coming from the sides of the screen. Staying at the same place in The Underworld, killing the various enemies around, seems to be the best way to get many lava critters.
*On platforms with stereo sound, critter sounds will indicate the critter's direction (left or right). This is particularly useful for various birds (including owls and ducks), and for frogs.
== Trivia ==
* Birds placed in a Terrarium peck in ascending order, the Blue Jay once, the Bird twice, the Cardinal three times and the Gold Bird four times.
* The Glowing Snail Cage emits a faint blue glow, similar to the one Jellyfish Necklace does when under water.
* The Bunny, Bird, Goldfish, and Penguin are the only four critters that have banners of themselves.
* All of the gem bunnies and squirrels are the same price when sold, despite representing gems of various, often higher prices.
* Before 1.4, the Gold Mouse was probably the rarest non-unique creature in the game; as of 1.4, the throne has probably been taken by either the Gold Seahorse or the Gold Water Strider.
== History ==