If you don't know what the heck a Bitbug is, this handy link should give you a good idea. Basically, these Kirbyesque bugs are living chaos, manifested in a cute, lovable, implacable, and infectious form. (For those curious, this question was inspired by the one answer I got to Figuring Out Monster Ecology, where you can find information on how fast Bitbug numbers grow. If not, the numbers will be provided in the Specifications for Best Answer).
These things are about the size of a giant jawbreaker (y'know, one that fills your entire hand when you hold it), and are round like them. Basically like a big, squishy pink bee but with big eyes and an even bigger mouth.
Now, my problem is not that Bitbugs are hard to eat. For one thing, they're about as numerous as ants in an anthill (if ants had 27 acre-anthills on average), eat just about anything, and have basically no survival instinct (due to having the Synergy enchantment, they don't really need to avoid being eaten). In other words, if a Bitbug ends up in something's mouth, it generally won't fight it but will instead go down under its own power. (The exception would be if they have a predator that is basically immune to Synergy, which is what this question is meant to create.)
The problem is the Synergy enchantment, which makes preying on a Bitbug a very bad idea. I have two ideas which concern overcoming this hurdle, but both of them have certain issues.
1. Soulitary Monster enchantments, released upon death on the weapon or creature that killed it, are A) held by the monster they come from and B) are based upon the monster's nature. A key example would be Plops, my rubbery take on fantasy slimes, and their Rubberization enchantment.
Soulitary is an enchantment exactly opposite of Synergy, which instead of bringing an object or creature into a community (which the Bithive kind of) brings it out. In other words, it exiles something, makes it an outcast, leaves it alone (read: renders it untouchable by Synergy).
However, this comes with a steep cost. A creature with Soulitary (I don't know what IRL animal would qualify, and I only have one monster that would qualify, the Whackagi) doesn't seek (or need) interaction with other members of its kind, and it doesn't work with other members of its kind either. It's just indifferent. (Obviously, this would be problematic for keeping the species alive; Whackagi don't exactly have that problem, being the result of Plop and Chomper fusion. Otherwise, Bitbugs could probably provide a way for Soulitary creatures to change their behavior when they need to mate.)
This is also problematic because A) Bitbugs can and will overcome something attacking them with sheer numbers, if that something is immune to Synergy and B) Bitbugs are, quite surprisingly, strong enough to easily lift and fly with a cinderblock. Even considering their body type, which doesn't exactly lend itself to inflicting injury, I'm pretty sure they can use that strength (and/or sheer numbers) to seriously injure a predator.
2. Loyalty Loyalty is an Enchantment held by an extremely loyal creature; in a world full of monsters, I figure that wolves and feral dogs at least will have this Enchantment, but there are other loyal creatures that could hold it, like: swans, gibbons, black vultures, French angelfish, and even prairie voles. Basically any species known for monogamy and loyalty could be a candidate.
Why does this matter? Because Loyalty would override Synergy, taking all of the good stuff about it but applying it to whatever that creature is naturally loyal to. This would allow wolves to develop a hive mind like Bitbugs have, and it would therefore be a huge evolutionary advantage. (This also could potentially enable rat swarms, since rats are rather social critters and according to rat lovers, very loyal too!)
I'm not sure if any insects would qualify for Loyalty, but if so, well, Loyalty might end up being another problem I need to address. In fact, perhaps humans could learn or be born with Loyalty (yes, humans in my setting have magic too, it's the force behind Classes and acquired and/or unique traits like Quickfooted, Triggerhappy, Composure, Organization....anyway, the thing is most of them don't have the capacity to cast spells, just to develop stronger than normal humans could on their own).
3. Other Enchantments:
Other animal traits could potentially negate Synergy. Perhaps a cat is too Willful or Independent to join a hive mind, or a goat is too dang Stubborn. (Goats will eat anything, right?)
Everything above considered, my question is: What Would Make The Best Bitbug Predator?
Specifications For Best Answer:
The best answer will account for the numbers, strength, and flight abilities of Bitbug, and especially the Synergy enchantment. Bitbug population depends on the Queen, the Bitbearer, which lays 2,400 eggs per day. These eggs then hatch into Bitbugs 48 hours after they were laid.
The best answer, obviously, needs to thoroughly analyze each potential Bitbug predator, select one or more 'best options,' and explain why they were chosen; why they would be the best predator (or predators) of Bitbugs. Things that qualify an animal as a good Bitbug predator include: voracious insect eating, big enough size to eat a Bitbug whole (or enough ferocity to take down and/or eat a Bitbug despite its small size), and loyalty, solitary nature, willfulness, stubbornness....
Durability and strength (to deal with a Bitbug's defenses and strength), flight (since Bitbug can fly), intelligence (since intelligence will help overcome sheer numbers if the predator doesn't have that), and so forth. Whackagi may be slow, very slow, but I believe they could be a good candidate due to their strength or durability.