Flies are very common enemies, found on almost every floor. They can also be spawned by various monsters and bosses, including
Duke of Flies,
The Husk,
Hives,
Swarmers,
Gurdy, and
Pestilence.
Skatole changes the behavior of most types of flies. The
Lord of The Flies transformation converts some types of flies into
Blue Flies.
Black flies buzz around the room randomly, often moving away from the player. They cannot damage Isaac at all, even by touch, making them completely harmless. However, they can turn into Pooters if they fly around poop for too long or come in contact with a golden poop.
Attack Flies are red and black flashing flies that will follow Isaac relentlessly until killed. Their only way of damaging Isaac is by contact, and they move rather slowly, making them easy to kill. However, they can be dangerous when found in groups, as they can swarm around Isaac quickly.
Attack Flies turn into regular Black Flies if Isaac has
Skatole. They take a small amount of time to convert into Black Flies, so it is possible for Isaac to be damaged if the player is not careful.
These have the exact same behavior as regular attack flies, and move at the same speed. However, they are larger and have more health than regular Attack Flies.
Dart Flies are similar to regular attack flies, but attempt to mimic Isaac's movements. Their only way of damaging Isaac is by contact, and they can move fairly quickly, making them potentially dangerous when found in groups.
Swarm Flies are similar to regular attack flies, but appear in tightly-packed clusters. Their only way of damaging Isaac is by contact, and although they move fairly slowly, they can be dangerous by simply outnumbering Isaac.
- If a Swarm Fly is separated from its group due to being petrified, it quickly moves back to its group once unpetrified.
Hush Flies are spawned by Hush and behave somewhat similarly to Ring Flies, flying as towards Isaac in certain patterns. Unlike Ring Flies, they can form other shapes such as polygons and can also orbit Hush.
Hush Flies have a brief period of invincibility when Hush spawns them, making them appear to have more health than they actually have.
Hush Flies are not affected by the Beelzebub Transformation.
Hush Flies can also rarely spawn outside of the Hush fight in rooms.
Moters appear as two Attack Flies joined together. They behave similarly to regular Attack Flies, but split into two Attack Flies upon being killed. Their split is very wide and unpredictable and can easily shave off half a heart. It is recommended to kill faster flies and other small monsters before it as the two flies it spawns are actually more dangerous in many ways. Running between them just as they split is also a very good way to dodge.
- If Isaac has Skatole, or uses a bomb, killing a Moter will not make them split into two Attack Flies.
The Eternal Fly is a white fly that can be found on any floor in the game. They usually circle corny poop or enemies like Holy Leeches and the Hanger and will not stop circling them until their hosts are destroyed. Before that, they will deal damage to Isaac if he touches them and are completely immune to all forms of damage. When their hosts are destroyed, they convert into Attack Flies.
- If Eternal Flies are circling Corny Poop and there are no other enemies around, you can leave the room at will. This is true even if they have already been converted into large attack flies: they will simply disappear when you return into the room.
Ring Flies are a new addition to Rebirth. They are pink flies that, upon entering the room, will cluster together into a circular formation and orbit rapidly while moving towards Isaac. They will hold formation even when you destroy all but one fly. The maximum amount of flies per formation is 10. These flies are fast and take up a large amount of space, so it may be recommended to hold these on higher danger priority.
- Ring Flies are not affected by
Strange Attractor and will continue to stay within their current circular formation.
Boom Flies roam around the room diagonally, dealing touch damage and exploding with a large blast radius upon death.
Skatole slows them down, but they remain dangerous. They also spawn from blue champion bosses such as
Fistula.
Flies around the room diagonally, dealing touch damage and exploding into 6 directional blood shots upon death.
Skatole will only slow down their movement.
Drowned Boom Flies fly around the room diagonally, dealing contact damage. Upon death, they explode, release 4 blood shots in the cardinal directions, and spawn a Drowned Charger. Occasionally the Drowned Charger will not spawn, and only blood shots will be fired.
If a Drowned Boom Fly dies while over an obstacle or pit, the Drowned Charger will not be spawned.
The Level 2 Fly flies towards Isaac somewhat erratically, dealing contact damage.
The Full Fly behaves similarly to the Level 2 Fly and Red Boom Fly combined, it chases Isaac and shoots 6 blood shots upon death. Full Flies do not run into Isaac, but will actually orbit around him closely until he moves, which may end up causing him to run into the fly.
The Pooter very slowly wanders around the room to the point where they basically stay put. They shoot one bullet at Isaac. Pooters will not shoot if Isaac wears
Skatole.
The Super Pooter behaves like the Pooter, except it shoots two bullets in a V-shaped pattern. Also does not shoot Isaac with
Skatole.
The Sucker has a greater amount of health than a regular fly, and slowly moves towards Isaac. Upon death it shoots 4 bullets in all cardinal directions. Suckers are unaffected by
Skatole, so they're always hostile.
Despite their simplistic behaviour, Suckers can actually prove rather dangerous in late levels. This is because often times they'll be positioned in areas containing hazards or the player may have familiars that attack the Suckers regardless of the player's intention. As a result, the low health that the Suckers possess can be used to give the player little time to react when they die quickly and shoot their projectiles outwards.
The Spit looks like a green version of the Sucker, and it shoots one explosive green bullet at the player upon death. The shot behaves exactly like
Ipecac. Spits are unaffected by
Skatole, so they're always hostile. Like most enemies that possess explosive attacks, Spits can be used to bomb
tinted rocks or open
Secret Rooms.
Soul Suckers were added in Booster Pack #4.
The Soul Sucker looks like a bloated, red-spotted version of the Sucker. Upon death, a swirling red vortex appears where it died, which then fires four
Brimstone beams in the four cardinal directions after a short delay.
The appearance of the vortex resembles the same vortex that is spawned whenever the player fires with
Brimstone and
Anti-Gravity.
- The Brimstone lasers from the Soul Suckers can damage other enemies, including other Soul Suckers. You should play carefully when facing multiple Soul Suckers, as their vortex attacks could corner you if you're not careful.
- The Black Fly has the lowest health of any enemy in the game, tied with the
Corn.
- There is a fly enemy in the Eternal Edition of the original Binding of Isaac that is a ball of 4 attack flies, resembling 2 Moters stuck to each other. This enemy does not appear in Rebirth.
- Suckers seem to be based on mosquitoes, midge like flies that suck the blood of other animals, as they seem to share a small proboscis and blood sac.
Bug! If a Pooter or a Super Pooter is
stunned at the same time that it tries to shoot Isaac, after the effect wears off, their shot will be fired without its corresponding animation.
Bug! If a Pooter or a Super Pooter is
stunned or
feared at the same time that it tries to shoot Isaac, its sound effect will repeat continuously until the effect is gone.
Attack Fly on Isaac's Last Will.
Concept art for the Soul Sucker.
Chaos Card, 
Little Horn
Euthanasia
_Icon.png){kind=icon}
Bug! If a Pooter or a Super Pooter is stunned at the same time that it tries to shoot Isaac, after the effect wears off, their shot will be fired without its corresponding animation.
The Binding of Isaac: Rebirth 
Achievements
Attributes
Bosses
Cards and Runes
Challenges
Chapters
Characters
Co-op
Items
Item Pools
Monsters
Objects
Pickups
Pills
Rooms
Seeds
Transformations
Trinkets
