First I just want to say, this game has a great feel. The graphics, animations, and music are all great. Definitely getting some SimAnt and Dungeon Keeper nostalgia playing it. I also think your level design is fantastic, every level is interesting and has a different theme. I do have a few suggestions however....

The game could use a similar upgrade system as in the formicarium, but for each level. Some upgrade trees and hard choices would be awesome. Some basic ones that last only for that level AND having the formicarium upgrades carry into each level would add many layers of depth. Sorta like how Starcraft 2 handles the campaign.

Secondly, just having food as a resource is limited. What if the resources were split into proteins and sugars. Smaller ants like workers could require no protein while larger soldiers ants would. Sugars could be gained from fruit that falls from trees, aphids farms, bee hives, nectar from flowers, ect. Sugars could be a slow but reliable form of food that you have to protect on the map.

Having more than just three unit types would go a long way. I realize it's hard to come up with more and keep it realistic. Maybe drones & new queens could produce royal jelly for research on upgrades? That would have to be specific to the level and wouldn't carry over but you would have to protect and they would slowly generate royal jelly (or generate it once when they fly out of the nest to establish new colonies).

Lastly, I'd love more of an underground threat presence. Currently, you attack targets at your leisure and you don't really have to be concerned about the underground. I'd love to see the underground baddies dig towards you and be a threat. Sort of like the hero gate in dungeon keeper II (if you played that).

1. Would be cool but would increase a lot the size of the inter-levels that are only made for learn the player how to play with the diffrent new colonies that will be added to the formicarium
2. That would be funny and more realistic but there would be two problems : firstly I think that modifying the resource system would be very difficult for the devs since it is already launched in several levels, secondly the adult ants do not consume Protein but only sugar it is the larvae that consume a lot of stuff for grow
3. I think that will be made but the mechanics of drones that drops royal jelly when the quit the nest and go forming a new colony would be awesome.
4. Like the crickets in the 1.1 level ?
In the game of ants, you play or you die.