I thought this was the issue I had also so I did kill them all using gas arrows thanks for the great tip on killing those glitched enemies this way.
Unluckily for me this still didn`t resolve the problem.
Thinking some more on the problem I realized I had done multiple runs through the ant hill killing everything I could and also out in the world.
Though one important thing I realized I didn't pick up their loot because by now I had so much Ant loot I had simply no need for more.
This disabled them to respawn so I went on a mission looting and trashing everything I could find to return in the evening without sleep (in-game).
And yay finally got lucky the kept on coming to lay eggs walked out with about 120.
Another thing I did do on the same day and am not sure if this might be related.
I went to the Larva cave during the day also and mass murdered them all. (using gas arrows)
For all the loot I had to create a dedicated storage container at the exit with a marker next to it to find it back easier.
So in closure I currently have the feeling not looting all the parts of a bug can prevent respawns.
NOTE: Loot it or trash it that's the question.
I will do some more testing but I know for Dandelions you need to fully remove and loot it all.
If you want them to regrow.
Grass also does not regrow when you leave the stock in the ground.
Something I will test now is to see if you can make wolf spiders stop from spawning (not looting their parts) .
*Easy mode activated* not so much Whoaa!!!
Some additional findings.
Dropping a mushroom from inventory on the ground.
Attracted Weevils to come for it.
So also need to do some more testing on this but it seems you can lure the insects you need when dropping specific foods.
I think the Ant`s like hotdogs bits as I saw them bringing those in the ant hill feeding section.
(close to the entrance)