Chicken are fed with soybeans. What would you feed ants so you can feed them to chicken in turn that would be more efficient?
The fish aspect seems more reasonable, if we can't figure out how to feed farmed fish with plant products.
Garbage.
What do they eat? Only the highest quality pre-consumer food waste will do. Rather than using animal by-products, we link up with juice bars, bakeries, breweries, and the likes to divert their food waste. While a mushy banana may not seem appetizing to you, our grubs would happily do the honors.
I grew up on a chicken and sheep farm. Between letting the chickens roam the vegetable part of the farm area and eat bugs (bonus: we didn't need pesticides) and feeding them our organic food waste, we basically spent nothing on chicken feed. I found out about chickens being zealous cannibals accidentally when I was a kid taking the trash out to feed them. We'd had fried chicken for dinner, and I wasn't thinking about it and just threw all the bones into the feeder like I always did with the food trash. They went berserk over those chicken bones. They absolutely loved them. It was a shark-style feeding frenzy. I was weirded out by that for a while.
It was a pretty small operation though. OP's idea for chickens might make sense in a factory farm situation where there's no space to let them roam for bugs. And maybe the logistics of getting them fresh trash don't make a ton of sense.
We used the chickens for eggs mostly and meat when they stopped laying. We used the sheep for meat every spring. We would trade with the neighbors in exchange for helping farm our vegetable crops or fresh milk from the small-ish dairy farm down the road. It wasn't the kind of thing where we were selling to a grocery conglomerate or anything.
Probably none of our farming practices would have been acceptable at scale. But that wasn't our point. It was mostly just for our family. Honestly, not the worst way to grow up. You farm your own food and slaughter your own meat. You learn a certain respect and appreciation for what sustains you.
But anyway, yeah, I don't know what the rules are if you're selling your livestock. Feeding them trash probably isn't allowed, even though it's efficient.
...why? I guarantee the ants don't care about this.
So if your food waste contains heavy metals (as another example) and you feed that to the ant larva and in turn feed the ant larva to fish, you're likely to end up with fish that have high levels of heavy metals.
Are you worried about chicken bones getting thrown away along with lead and mercury, and picking those metals up before being fed to the ants?